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\begin{isabellebody}%

\def\isabellecontext{Build{\isaliteral{5F}{\isacharunderscore}}Inverse{\isaliteral{5F}{\isacharunderscore}}Z{\isaliteral{5F}{\isacharunderscore}}Transform}%

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\isadelimtheory

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\endisadelimtheory

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\isatagtheory

\isacommand{theory}\isamarkupfalse%

\ Build{\isaliteral{5F}{\isacharunderscore}}Inverse{\isaliteral{5F}{\isacharunderscore}}Z{\isaliteral{5F}{\isacharunderscore}}Transform\ \isakeyword{imports}\ Isac\isanewline

\ \ \isanewline

\isakeyword{begin}%

\endisatagtheory

{\isafoldtheory}%

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\endisadelimtheory

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\begin{isamarkuptext}%

We stepwise build \ttfamily Inverse\_Z\_Transform.thy \normalfont as an 

  exercise. Because subsection~\ref{sec:stepcheck} requires 

  \ttfamily Inverse\_Z\_Transform.thy \normalfont as a subtheory of \ttfamily 

  Isac.thy\normalfont, the setup has been changed from \ttfamily theory 

  Inverse\_Z\_Transform imports Isac \normalfont to the above one.

  \par \noindent

  \begin{center} 

  \textbf{ATTENTION WITH NAMES OF IDENTIFIERS WHEN GOING INTO INTERNALS}

  \end{center}

  Here in this theory there are the internal names twice, for instance we have

  \ttfamily (Thm.derivation\_name \isa{rule{\isadigit{1}}} = 

  "Build\_Inverse\_Z\_Transform.rule1") = true; \normalfont

  but actually in us will be \ttfamily Inverse\_Z\_Transform.rule1 \normalfont%

\end{isamarkuptext}%

\isamarkuptrue%

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\isamarkupsection{Trials towards the Z-Transform\label{sec:trials}%

}

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\endisadelimML

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\isacommand{ML}\isamarkupfalse%

\ {\isaliteral{7B2A}{\isacharverbatimopen}}val\ thy\ {\isaliteral{3D}{\isacharequal}}\ %

\isaantiq

theory\ Isac{}%

\endisaantiq

{\isaliteral{3B}{\isacharsemicolon}}{\isaliteral{2A7D}{\isacharverbatimclose}}%

\endisatagML

{\isafoldML}%

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\isamarkupsubsection{Notations and Terms%

}

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\begin{isamarkuptext}%

\noindent Try which notations we are able to use.%

\end{isamarkuptext}%

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\isacommand{ML}\isamarkupfalse%

\ {\isaliteral{7B2A}{\isacharverbatimopen}}\isanewline

\ \ %

\isaantiq

term\ {\isaliteral{22}{\isachardoublequote}}{\isadigit{1}}\ {\isaliteral{3C}{\isacharless}}\ {\isaliteral{7C}{\isacharbar}}{\isaliteral{7C}{\isacharbar}}\ z\ {\isaliteral{7C}{\isacharbar}}{\isaliteral{7C}{\isacharbar}}{\isaliteral{22}{\isachardoublequote}}{}%

\endisaantiq

{\isaliteral{3B}{\isacharsemicolon}}\isanewline

\ \ %

\isaantiq

term\ {\isaliteral{22}{\isachardoublequote}}z\ {\isaliteral{2F}{\isacharslash}}\ {\isaliteral{28}{\isacharparenleft}}z\ {\isaliteral{2D}{\isacharminus}}\ {\isadigit{1}}{\isaliteral{29}{\isacharparenright}}{\isaliteral{22}{\isachardoublequote}}{}%

\endisaantiq

{\isaliteral{3B}{\isacharsemicolon}}\isanewline

\ \ %

\isaantiq

term\ {\isaliteral{22}{\isachardoublequote}}{\isaliteral{2D}{\isacharminus}}u\ {\isaliteral{2D}{\isacharminus}}n\ {\isaliteral{2D}{\isacharminus}}\ {\isadigit{1}}{\isaliteral{22}{\isachardoublequote}}{}%

\endisaantiq

{\isaliteral{3B}{\isacharsemicolon}}\isanewline

\ \ %

\isaantiq

term\ {\isaliteral{22}{\isachardoublequote}}{\isaliteral{2D}{\isacharminus}}u\ {\isaliteral{5B}{\isacharbrackleft}}{\isaliteral{2D}{\isacharminus}}n\ {\isaliteral{2D}{\isacharminus}}\ {\isadigit{1}}{\isaliteral{5D}{\isacharbrackright}}{\isaliteral{22}{\isachardoublequote}}{}%

\endisaantiq

{\isaliteral{3B}{\isacharsemicolon}}\ {\isaliteral{28}{\isacharparenleft}}{\isaliteral{2A}{\isacharasterisk}}{\isaliteral{5B}{\isacharbrackleft}}\ {\isaliteral{5D}{\isacharbrackright}}\ denotes\ lists\ {\isaliteral{21}{\isacharbang}}{\isaliteral{21}{\isacharbang}}{\isaliteral{21}{\isacharbang}}{\isaliteral{2A}{\isacharasterisk}}{\isaliteral{29}{\isacharparenright}}\isanewline

\ \ %

\isaantiq

term\ {\isaliteral{22}{\isachardoublequote}}z\ {\isaliteral{2F}{\isacharslash}}{\isaliteral{28}{\isacharparenleft}}z\ {\isaliteral{2D}{\isacharminus}}\ {\isadigit{1}}{\isaliteral{29}{\isacharparenright}}\ {\isaliteral{3D}{\isacharequal}}\ {\isaliteral{2D}{\isacharminus}}u\ {\isaliteral{5B}{\isacharbrackleft}}{\isaliteral{2D}{\isacharminus}}n\ {\isaliteral{2D}{\isacharminus}}\ {\isadigit{1}}{\isaliteral{5D}{\isacharbrackright}}{\isaliteral{22}{\isachardoublequote}}{}%

\endisaantiq

{\isaliteral{3B}{\isacharsemicolon}}Isac\isanewline

\ \ %

\isaantiq

term\ {\isaliteral{22}{\isachardoublequote}}{\isadigit{1}}\ {\isaliteral{3C}{\isacharless}}\ {\isaliteral{7C}{\isacharbar}}{\isaliteral{7C}{\isacharbar}}\ z\ {\isaliteral{7C}{\isacharbar}}{\isaliteral{7C}{\isacharbar}}\ {\isaliteral{3D}{\isacharequal}}{\isaliteral{3D}{\isacharequal}}{\isaliteral{3E}{\isachargreater}}\ z\ {\isaliteral{2F}{\isacharslash}}\ {\isaliteral{28}{\isacharparenleft}}z\ {\isaliteral{2D}{\isacharminus}}\ {\isadigit{1}}{\isaliteral{29}{\isacharparenright}}\ {\isaliteral{3D}{\isacharequal}}\ {\isaliteral{2D}{\isacharminus}}u\ {\isaliteral{5B}{\isacharbrackleft}}{\isaliteral{2D}{\isacharminus}}n\ {\isaliteral{2D}{\isacharminus}}\ {\isadigit{1}}{\isaliteral{5D}{\isacharbrackright}}{\isaliteral{22}{\isachardoublequote}}{}%

\endisaantiq

{\isaliteral{3B}{\isacharsemicolon}}\isanewline

\ \ term{\isadigit{2}}str\ %

\isaantiq

term\ {\isaliteral{22}{\isachardoublequote}}{\isadigit{1}}\ {\isaliteral{3C}{\isacharless}}\ {\isaliteral{7C}{\isacharbar}}{\isaliteral{7C}{\isacharbar}}\ z\ {\isaliteral{7C}{\isacharbar}}{\isaliteral{7C}{\isacharbar}}\ {\isaliteral{3D}{\isacharequal}}{\isaliteral{3D}{\isacharequal}}{\isaliteral{3E}{\isachargreater}}\ z\ {\isaliteral{2F}{\isacharslash}}\ {\isaliteral{28}{\isacharparenleft}}z\ {\isaliteral{2D}{\isacharminus}}\ {\isadigit{1}}{\isaliteral{29}{\isacharparenright}}\ {\isaliteral{3D}{\isacharequal}}\ {\isaliteral{2D}{\isacharminus}}u\ {\isaliteral{5B}{\isacharbrackleft}}{\isaliteral{2D}{\isacharminus}}n\ {\isaliteral{2D}{\isacharminus}}\ {\isadigit{1}}{\isaliteral{5D}{\isacharbrackright}}{\isaliteral{22}{\isachardoublequote}}{}%

\endisaantiq

{\isaliteral{3B}{\isacharsemicolon}}\isanewline

{\isaliteral{2A7D}{\isacharverbatimclose}}%

\endisatagML

{\isafoldML}%

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\begin{isamarkuptext}%

\noindent Try which symbols we are able to use and how we generate them.%

\end{isamarkuptext}%

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\isatagML

\isacommand{ML}\isamarkupfalse%

\ {\isaliteral{7B2A}{\isacharverbatimopen}}\isanewline

\ \ {\isaliteral{28}{\isacharparenleft}}{\isaliteral{2A}{\isacharasterisk}}alpha\ {\isaliteral{2D}{\isacharminus}}{\isaliteral{2D}{\isacharminus}}{\isaliteral{3E}{\isachargreater}}\ \ {\isaliteral{22}{\isachardoublequote}}{\isaliteral{3C}{\isacharless}}{\isaliteral{2F}{\isacharslash}}alpha{\isaliteral{3E}{\isachargreater}}{\isaliteral{22}{\isachardoublequote}}\ {\isaliteral{2A}{\isacharasterisk}}{\isaliteral{29}{\isacharparenright}}\isanewline

\ \ %

\isaantiq

term\ {\isaliteral{22}{\isachardoublequote}}{\isaliteral{5C3C616C7068613E}{\isasymalpha}}\ {\isaliteral{22}{\isachardoublequote}}{}%

\endisaantiq

{\isaliteral{3B}{\isacharsemicolon}}\isanewline

\ \ %

\isaantiq

term\ {\isaliteral{22}{\isachardoublequote}}{\isaliteral{5C3C64656C74613E}{\isasymdelta}}\ {\isaliteral{22}{\isachardoublequote}}{}%

\endisaantiq

{\isaliteral{3B}{\isacharsemicolon}}\isanewline

\ \ %

\isaantiq

term\ {\isaliteral{22}{\isachardoublequote}}{\isaliteral{5C3C7068693E}{\isasymphi}}\ {\isaliteral{22}{\isachardoublequote}}{}%

\endisaantiq

{\isaliteral{3B}{\isacharsemicolon}}\isanewline

\ \ %

\isaantiq

term\ {\isaliteral{22}{\isachardoublequote}}{\isaliteral{5C3C72686F3E}{\isasymrho}}\ {\isaliteral{22}{\isachardoublequote}}{}%

\endisaantiq

{\isaliteral{3B}{\isacharsemicolon}}\isanewline

\ \ term{\isadigit{2}}str\ %

\isaantiq

term\ {\isaliteral{22}{\isachardoublequote}}{\isaliteral{5C3C72686F3E}{\isasymrho}}\ {\isaliteral{22}{\isachardoublequote}}{}%

\endisaantiq

{\isaliteral{3B}{\isacharsemicolon}}\isanewline

{\isaliteral{2A7D}{\isacharverbatimclose}}%

\endisatagML

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\isamarkupsubsection{Rules%

}

\isamarkuptrue%

\isacommand{axiomatization}\isamarkupfalse%

\ \isakeyword{where}\ \isanewline

\ \ rule{\isadigit{1}}{\isaliteral{3A}{\isacharcolon}}\ {\isaliteral{22}{\isachardoublequoteopen}}{\isadigit{1}}\ {\isaliteral{3D}{\isacharequal}}\ {\isaliteral{5C3C64656C74613E}{\isasymdelta}}{\isaliteral{5B}{\isacharbrackleft}}n{\isaliteral{5D}{\isacharbrackright}}{\isaliteral{22}{\isachardoublequoteclose}}\ \isakeyword{and}\isanewline

\ \ rule{\isadigit{2}}{\isaliteral{3A}{\isacharcolon}}\ {\isaliteral{22}{\isachardoublequoteopen}}{\isaliteral{7C}{\isacharbar}}{\isaliteral{7C}{\isacharbar}}\ z\ {\isaliteral{7C}{\isacharbar}}{\isaliteral{7C}{\isacharbar}}\ {\isaliteral{3E}{\isachargreater}}\ {\isadigit{1}}\ {\isaliteral{3D}{\isacharequal}}{\isaliteral{3D}{\isacharequal}}{\isaliteral{3E}{\isachargreater}}\ z\ {\isaliteral{2F}{\isacharslash}}\ {\isaliteral{28}{\isacharparenleft}}z\ {\isaliteral{2D}{\isacharminus}}\ {\isadigit{1}}{\isaliteral{29}{\isacharparenright}}\ {\isaliteral{3D}{\isacharequal}}\ u\ {\isaliteral{5B}{\isacharbrackleft}}n{\isaliteral{5D}{\isacharbrackright}}{\isaliteral{22}{\isachardoublequoteclose}}\ \isakeyword{and}\isanewline

\ \ rule{\isadigit{3}}{\isaliteral{3A}{\isacharcolon}}\ {\isaliteral{22}{\isachardoublequoteopen}}{\isaliteral{7C}{\isacharbar}}{\isaliteral{7C}{\isacharbar}}\ z\ {\isaliteral{7C}{\isacharbar}}{\isaliteral{7C}{\isacharbar}}\ {\isaliteral{3C}{\isacharless}}\ {\isadigit{1}}\ {\isaliteral{3D}{\isacharequal}}{\isaliteral{3D}{\isacharequal}}{\isaliteral{3E}{\isachargreater}}\ z\ {\isaliteral{2F}{\isacharslash}}\ {\isaliteral{28}{\isacharparenleft}}z\ {\isaliteral{2D}{\isacharminus}}\ {\isadigit{1}}{\isaliteral{29}{\isacharparenright}}\ {\isaliteral{3D}{\isacharequal}}\ {\isaliteral{2D}{\isacharminus}}u\ {\isaliteral{5B}{\isacharbrackleft}}{\isaliteral{2D}{\isacharminus}}n\ {\isaliteral{2D}{\isacharminus}}\ {\isadigit{1}}{\isaliteral{5D}{\isacharbrackright}}{\isaliteral{22}{\isachardoublequoteclose}}\ \isakeyword{and}\ \isanewline

\ \ rule{\isadigit{4}}{\isaliteral{3A}{\isacharcolon}}\ {\isaliteral{22}{\isachardoublequoteopen}}{\isaliteral{7C}{\isacharbar}}{\isaliteral{7C}{\isacharbar}}\ z\ {\isaliteral{7C}{\isacharbar}}{\isaliteral{7C}{\isacharbar}}\ {\isaliteral{3E}{\isachargreater}}\ {\isaliteral{7C}{\isacharbar}}{\isaliteral{7C}{\isacharbar}}\ {\isaliteral{5C3C616C7068613E}{\isasymalpha}}\ {\isaliteral{7C}{\isacharbar}}{\isaliteral{7C}{\isacharbar}}\ {\isaliteral{3D}{\isacharequal}}{\isaliteral{3D}{\isacharequal}}{\isaliteral{3E}{\isachargreater}}\ z\ {\isaliteral{2F}{\isacharslash}}\ {\isaliteral{28}{\isacharparenleft}}z\ {\isaliteral{2D}{\isacharminus}}\ {\isaliteral{5C3C616C7068613E}{\isasymalpha}}{\isaliteral{29}{\isacharparenright}}\ {\isaliteral{3D}{\isacharequal}}\ {\isaliteral{5C3C616C7068613E}{\isasymalpha}}{\isaliteral{5E}{\isacharcircum}}{\isaliteral{5E}{\isacharcircum}}{\isaliteral{5E}{\isacharcircum}}n\ {\isaliteral{2A}{\isacharasterisk}}\ u\ {\isaliteral{5B}{\isacharbrackleft}}n{\isaliteral{5D}{\isacharbrackright}}{\isaliteral{22}{\isachardoublequoteclose}}\ \isakeyword{and}\isanewline

\ \ rule{\isadigit{5}}{\isaliteral{3A}{\isacharcolon}}\ {\isaliteral{22}{\isachardoublequoteopen}}{\isaliteral{7C}{\isacharbar}}{\isaliteral{7C}{\isacharbar}}\ z\ {\isaliteral{7C}{\isacharbar}}{\isaliteral{7C}{\isacharbar}}\ {\isaliteral{3C}{\isacharless}}\ {\isaliteral{7C}{\isacharbar}}{\isaliteral{7C}{\isacharbar}}\ {\isaliteral{5C3C616C7068613E}{\isasymalpha}}\ {\isaliteral{7C}{\isacharbar}}{\isaliteral{7C}{\isacharbar}}\ {\isaliteral{3D}{\isacharequal}}{\isaliteral{3D}{\isacharequal}}{\isaliteral{3E}{\isachargreater}}\ z\ {\isaliteral{2F}{\isacharslash}}\ {\isaliteral{28}{\isacharparenleft}}z\ {\isaliteral{2D}{\isacharminus}}\ {\isaliteral{5C3C616C7068613E}{\isasymalpha}}{\isaliteral{29}{\isacharparenright}}\ {\isaliteral{3D}{\isacharequal}}\ {\isaliteral{2D}{\isacharminus}}{\isaliteral{28}{\isacharparenleft}}{\isaliteral{5C3C616C7068613E}{\isasymalpha}}{\isaliteral{5E}{\isacharcircum}}{\isaliteral{5E}{\isacharcircum}}{\isaliteral{5E}{\isacharcircum}}n{\isaliteral{29}{\isacharparenright}}\ {\isaliteral{2A}{\isacharasterisk}}\ u\ {\isaliteral{5B}{\isacharbrackleft}}{\isaliteral{2D}{\isacharminus}}n\ {\isaliteral{2D}{\isacharminus}}\ {\isadigit{1}}{\isaliteral{5D}{\isacharbrackright}}{\isaliteral{22}{\isachardoublequoteclose}}\ \isakeyword{and}\isanewline

\ \ rule{\isadigit{6}}{\isaliteral{3A}{\isacharcolon}}\ {\isaliteral{22}{\isachardoublequoteopen}}{\isaliteral{7C}{\isacharbar}}{\isaliteral{7C}{\isacharbar}}\ z\ {\isaliteral{7C}{\isacharbar}}{\isaliteral{7C}{\isacharbar}}\ {\isaliteral{3E}{\isachargreater}}\ {\isadigit{1}}\ {\isaliteral{3D}{\isacharequal}}{\isaliteral{3D}{\isacharequal}}{\isaliteral{3E}{\isachargreater}}\ z{\isaliteral{2F}{\isacharslash}}{\isaliteral{28}{\isacharparenleft}}z\ {\isaliteral{2D}{\isacharminus}}\ {\isadigit{1}}{\isaliteral{29}{\isacharparenright}}{\isaliteral{5E}{\isacharcircum}}{\isaliteral{5E}{\isacharcircum}}{\isaliteral{5E}{\isacharcircum}}{\isadigit{2}}\ {\isaliteral{3D}{\isacharequal}}\ n\ {\isaliteral{2A}{\isacharasterisk}}\ u\ {\isaliteral{5B}{\isacharbrackleft}}n{\isaliteral{5D}{\isacharbrackright}}{\isaliteral{22}{\isachardoublequoteclose}}%

\begin{isamarkuptext}%

\noindent Check the rules for their correct notation. 

      (See the machine output.)%

\end{isamarkuptext}%

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\endisadelimML

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\isatagML

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\ {\isaliteral{7B2A}{\isacharverbatimopen}}\isanewline

\ \ %

\isaantiq

thm\ rule{\isadigit{1}}{}%

\endisaantiq

{\isaliteral{3B}{\isacharsemicolon}}\isanewline

\ \ %

\isaantiq

thm\ rule{\isadigit{2}}{}%

\endisaantiq

{\isaliteral{3B}{\isacharsemicolon}}\isanewline

\ \ %

\isaantiq

thm\ rule{\isadigit{3}}{}%

\endisaantiq

{\isaliteral{3B}{\isacharsemicolon}}\isanewline

\ \ %

\isaantiq

thm\ rule{\isadigit{4}}{}%

\endisaantiq

{\isaliteral{3B}{\isacharsemicolon}}\isanewline

{\isaliteral{2A7D}{\isacharverbatimclose}}%

\endisatagML

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\isamarkupsubsection{Apply Rules%

}

\isamarkuptrue%

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\begin{isamarkuptext}%

\noindent We try to apply the rules to a given expression.%

\end{isamarkuptext}%

\isamarkuptrue%

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\isadelimML

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\endisadelimML

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\isatagML

\isacommand{ML}\isamarkupfalse%

\ {\isaliteral{7B2A}{\isacharverbatimopen}}\isanewline

\ \ val\ inverse{\isaliteral{5F}{\isacharunderscore}}Z\ {\isaliteral{3D}{\isacharequal}}\ append{\isaliteral{5F}{\isacharunderscore}}rls\ {\isaliteral{22}{\isachardoublequote}}inverse{\isaliteral{5F}{\isacharunderscore}}Z{\isaliteral{22}{\isachardoublequote}}\ e{\isaliteral{5F}{\isacharunderscore}}rls\isanewline

\ \ \ \ {\isaliteral{5B}{\isacharbrackleft}}\ Thm\ \ {\isaliteral{28}{\isacharparenleft}}{\isaliteral{22}{\isachardoublequote}}rule{\isadigit{3}}{\isaliteral{22}{\isachardoublequote}}{\isaliteral{2C}{\isacharcomma}}num{\isaliteral{5F}{\isacharunderscore}}str\ %

\isaantiq

thm\ rule{\isadigit{3}}{}%

\endisaantiq

{\isaliteral{29}{\isacharparenright}}{\isaliteral{2C}{\isacharcomma}}\isanewline

\ \ \ \ \ \ Thm\ \ {\isaliteral{28}{\isacharparenleft}}{\isaliteral{22}{\isachardoublequote}}rule{\isadigit{4}}{\isaliteral{22}{\isachardoublequote}}{\isaliteral{2C}{\isacharcomma}}num{\isaliteral{5F}{\isacharunderscore}}str\ %

\isaantiq

thm\ rule{\isadigit{4}}{}%

\endisaantiq

{\isaliteral{29}{\isacharparenright}}{\isaliteral{2C}{\isacharcomma}}\isanewline

\ \ \ \ \ \ Thm\ \ {\isaliteral{28}{\isacharparenleft}}{\isaliteral{22}{\isachardoublequote}}rule{\isadigit{1}}{\isaliteral{22}{\isachardoublequote}}{\isaliteral{2C}{\isacharcomma}}num{\isaliteral{5F}{\isacharunderscore}}str\ %

\isaantiq

thm\ rule{\isadigit{1}}{}%

\endisaantiq

{\isaliteral{29}{\isacharparenright}}\ \ \ \isanewline

\ \ \ \ {\isaliteral{5D}{\isacharbrackright}}{\isaliteral{3B}{\isacharsemicolon}}\isanewline

\isanewline

\ \ val\ t\ {\isaliteral{3D}{\isacharequal}}\ str{\isadigit{2}}term\ {\isaliteral{22}{\isachardoublequote}}z\ {\isaliteral{2F}{\isacharslash}}\ {\isaliteral{28}{\isacharparenleft}}z\ {\isaliteral{2D}{\isacharminus}}\ {\isadigit{1}}{\isaliteral{29}{\isacharparenright}}\ {\isaliteral{2B}{\isacharplus}}\ z\ {\isaliteral{2F}{\isacharslash}}\ {\isaliteral{28}{\isacharparenleft}}z\ {\isaliteral{2D}{\isacharminus}}\ {\isaliteral{5C3C616C7068613E}{\isasymalpha}}{\isaliteral{29}{\isacharparenright}}\ {\isaliteral{2B}{\isacharplus}}\ {\isadigit{1}}{\isaliteral{22}{\isachardoublequote}}{\isaliteral{3B}{\isacharsemicolon}}\isanewline

\ \ val\ SOME\ {\isaliteral{28}{\isacharparenleft}}t{\isaliteral{27}{\isacharprime}}{\isaliteral{2C}{\isacharcomma}}\ asm{\isaliteral{29}{\isacharparenright}}\ {\isaliteral{3D}{\isacharequal}}\ rewrite{\isaliteral{5F}{\isacharunderscore}}set{\isaliteral{5F}{\isacharunderscore}}\ thy\ true\ inverse{\isaliteral{5F}{\isacharunderscore}}Z\ t{\isaliteral{3B}{\isacharsemicolon}}\isanewline

\ \ term{\isadigit{2}}str\ t{\isaliteral{27}{\isacharprime}}\ {\isaliteral{3D}{\isacharequal}}\ {\isaliteral{22}{\isachardoublequote}}z\ {\isaliteral{2F}{\isacharslash}}\ {\isaliteral{28}{\isacharparenleft}}z\ {\isaliteral{2D}{\isacharminus}}\ {\isaliteral{3F}{\isacharquery}}{\isaliteral{5C3C64656C74613E}{\isasymdelta}}\ {\isaliteral{5B}{\isacharbrackleft}}{\isaliteral{3F}{\isacharquery}}n{\isaliteral{5D}{\isacharbrackright}}{\isaliteral{29}{\isacharparenright}}\ {\isaliteral{2B}{\isacharplus}}\ z\ {\isaliteral{2F}{\isacharslash}}\ {\isaliteral{28}{\isacharparenleft}}z\ {\isaliteral{2D}{\isacharminus}}\ {\isaliteral{5C3C616C7068613E}{\isasymalpha}}{\isaliteral{29}{\isacharparenright}}\ {\isaliteral{2B}{\isacharplus}}\ {\isaliteral{3F}{\isacharquery}}{\isaliteral{5C3C64656C74613E}{\isasymdelta}}\ {\isaliteral{5B}{\isacharbrackleft}}{\isaliteral{3F}{\isacharquery}}n{\isaliteral{5D}{\isacharbrackright}}{\isaliteral{22}{\isachardoublequote}}{\isaliteral{3B}{\isacharsemicolon}}\isanewline

\ \ {\isaliteral{28}{\isacharparenleft}}{\isaliteral{2A}{\isacharasterisk}}\isanewline

\ \ \ {\isaliteral{2A}{\isacharasterisk}}\ Attention\ rule{\isadigit{1}}\ is\ applied\ before\ the\ expression\ is\ \isanewline

\ \ \ {\isaliteral{2A}{\isacharasterisk}}\ checked\ for\ rule{\isadigit{4}}\ which\ would\ be\ correct{\isaliteral{21}{\isacharbang}}{\isaliteral{21}{\isacharbang}}{\isaliteral{21}{\isacharbang}}\isanewline

\ \ \ {\isaliteral{2A}{\isacharasterisk}}{\isaliteral{29}{\isacharparenright}}\isanewline

{\isaliteral{2A7D}{\isacharverbatimclose}}\isanewline

\isanewline

\isacommand{ML}\isamarkupfalse%

\ {\isaliteral{7B2A}{\isacharverbatimopen}}\ val\ {\isaliteral{28}{\isacharparenleft}}thy{\isaliteral{2C}{\isacharcomma}}\ ro{\isaliteral{2C}{\isacharcomma}}\ er{\isaliteral{29}{\isacharparenright}}\ {\isaliteral{3D}{\isacharequal}}\ {\isaliteral{28}{\isacharparenleft}}%

\isaantiq

theory\ Isac{}%

\endisaantiq

{\isaliteral{2C}{\isacharcomma}}\ tless{\isaliteral{5F}{\isacharunderscore}}true{\isaliteral{2C}{\isacharcomma}}\ eval{\isaliteral{5F}{\isacharunderscore}}rls{\isaliteral{29}{\isacharparenright}}{\isaliteral{3B}{\isacharsemicolon}}\ {\isaliteral{2A7D}{\isacharverbatimclose}}\isanewline

\isacommand{ML}\isamarkupfalse%

\ {\isaliteral{7B2A}{\isacharverbatimopen}}\isanewline

\ \ val\ SOME\ {\isaliteral{28}{\isacharparenleft}}t{\isaliteral{2C}{\isacharcomma}}\ asm{\isadigit{1}}{\isaliteral{29}{\isacharparenright}}\ {\isaliteral{3D}{\isacharequal}}\ \isanewline

\ \ \ \ rewrite{\isaliteral{5F}{\isacharunderscore}}\ thy\ ro\ er\ true\ {\isaliteral{28}{\isacharparenleft}}num{\isaliteral{5F}{\isacharunderscore}}str\ %

\isaantiq

thm\ rule{\isadigit{3}}{}%

\endisaantiq

{\isaliteral{29}{\isacharparenright}}\ t{\isaliteral{3B}{\isacharsemicolon}}\isanewline

\ \ term{\isadigit{2}}str\ t\ {\isaliteral{3D}{\isacharequal}}\ {\isaliteral{22}{\isachardoublequote}}{\isaliteral{2D}{\isacharminus}}\ {\isaliteral{3F}{\isacharquery}}u\ {\isaliteral{5B}{\isacharbrackleft}}{\isaliteral{2D}{\isacharminus}}\ {\isaliteral{3F}{\isacharquery}}n\ {\isaliteral{2D}{\isacharminus}}\ {\isadigit{1}}{\isaliteral{5D}{\isacharbrackright}}\ {\isaliteral{2B}{\isacharplus}}\ z\ {\isaliteral{2F}{\isacharslash}}\ {\isaliteral{28}{\isacharparenleft}}z\ {\isaliteral{2D}{\isacharminus}}\ {\isaliteral{5C3C616C7068613E}{\isasymalpha}}{\isaliteral{29}{\isacharparenright}}\ {\isaliteral{2B}{\isacharplus}}\ {\isadigit{1}}{\isaliteral{22}{\isachardoublequote}}{\isaliteral{3B}{\isacharsemicolon}}\isanewline

\ \ {\isaliteral{28}{\isacharparenleft}}{\isaliteral{2A}{\isacharasterisk}}{\isaliteral{2D}{\isacharminus}}\ real\ {\isaliteral{2A}{\isacharasterisk}}{\isaliteral{29}{\isacharparenright}}\isanewline

\ \ term{\isadigit{2}}str\ t{\isaliteral{3B}{\isacharsemicolon}}\isanewline

\isanewline

\ \ val\ SOME\ {\isaliteral{28}{\isacharparenleft}}t{\isaliteral{2C}{\isacharcomma}}\ asm{\isadigit{2}}{\isaliteral{29}{\isacharparenright}}\ {\isaliteral{3D}{\isacharequal}}\ \isanewline

\ \ \ \ rewrite{\isaliteral{5F}{\isacharunderscore}}\ thy\ ro\ er\ true\ {\isaliteral{28}{\isacharparenleft}}num{\isaliteral{5F}{\isacharunderscore}}str\ %

\isaantiq

thm\ rule{\isadigit{4}}{}%

\endisaantiq

{\isaliteral{29}{\isacharparenright}}\ t{\isaliteral{3B}{\isacharsemicolon}}\isanewline

\ \ term{\isadigit{2}}str\ t\ {\isaliteral{3D}{\isacharequal}}\ {\isaliteral{22}{\isachardoublequote}}{\isaliteral{2D}{\isacharminus}}\ {\isaliteral{3F}{\isacharquery}}u\ {\isaliteral{5B}{\isacharbrackleft}}{\isaliteral{2D}{\isacharminus}}\ {\isaliteral{3F}{\isacharquery}}n\ {\isaliteral{2D}{\isacharminus}}\ {\isadigit{1}}{\isaliteral{5D}{\isacharbrackright}}\ {\isaliteral{2B}{\isacharplus}}\ {\isaliteral{5C3C616C7068613E}{\isasymalpha}}\ {\isaliteral{5E}{\isacharcircum}}{\isaliteral{5E}{\isacharcircum}}{\isaliteral{5E}{\isacharcircum}}\ {\isaliteral{3F}{\isacharquery}}n\ {\isaliteral{2A}{\isacharasterisk}}\ {\isaliteral{3F}{\isacharquery}}u\ {\isaliteral{5B}{\isacharbrackleft}}{\isaliteral{3F}{\isacharquery}}n{\isaliteral{5D}{\isacharbrackright}}\ {\isaliteral{2B}{\isacharplus}}\ {\isadigit{1}}{\isaliteral{22}{\isachardoublequote}}{\isaliteral{3B}{\isacharsemicolon}}\isanewline

\ \ {\isaliteral{28}{\isacharparenleft}}{\isaliteral{2A}{\isacharasterisk}}{\isaliteral{2D}{\isacharminus}}\ real\ {\isaliteral{2A}{\isacharasterisk}}{\isaliteral{29}{\isacharparenright}}\isanewline

\ \ term{\isadigit{2}}str\ t{\isaliteral{3B}{\isacharsemicolon}}\isanewline

\isanewline

\ \ val\ SOME\ {\isaliteral{28}{\isacharparenleft}}t{\isaliteral{2C}{\isacharcomma}}\ asm{\isadigit{3}}{\isaliteral{29}{\isacharparenright}}\ {\isaliteral{3D}{\isacharequal}}\ \isanewline

\ \ \ \ rewrite{\isaliteral{5F}{\isacharunderscore}}\ thy\ ro\ er\ true\ {\isaliteral{28}{\isacharparenleft}}num{\isaliteral{5F}{\isacharunderscore}}str\ %

\isaantiq

thm\ rule{\isadigit{1}}{}%

\endisaantiq

{\isaliteral{29}{\isacharparenright}}\ t{\isaliteral{3B}{\isacharsemicolon}}\isanewline

\ \ term{\isadigit{2}}str\ t\ {\isaliteral{3D}{\isacharequal}}\ {\isaliteral{22}{\isachardoublequote}}{\isaliteral{2D}{\isacharminus}}\ {\isaliteral{3F}{\isacharquery}}u\ {\isaliteral{5B}{\isacharbrackleft}}{\isaliteral{2D}{\isacharminus}}\ {\isaliteral{3F}{\isacharquery}}n\ {\isaliteral{2D}{\isacharminus}}\ {\isadigit{1}}{\isaliteral{5D}{\isacharbrackright}}\ {\isaliteral{2B}{\isacharplus}}\ {\isaliteral{5C3C616C7068613E}{\isasymalpha}}\ {\isaliteral{5E}{\isacharcircum}}{\isaliteral{5E}{\isacharcircum}}{\isaliteral{5E}{\isacharcircum}}\ {\isaliteral{3F}{\isacharquery}}n\ {\isaliteral{2A}{\isacharasterisk}}\ {\isaliteral{3F}{\isacharquery}}u\ {\isaliteral{5B}{\isacharbrackleft}}{\isaliteral{3F}{\isacharquery}}n{\isaliteral{5D}{\isacharbrackright}}\ {\isaliteral{2B}{\isacharplus}}\ {\isaliteral{3F}{\isacharquery}}{\isaliteral{5C3C64656C74613E}{\isasymdelta}}\ {\isaliteral{5B}{\isacharbrackleft}}{\isaliteral{3F}{\isacharquery}}n{\isaliteral{5D}{\isacharbrackright}}{\isaliteral{22}{\isachardoublequote}}{\isaliteral{3B}{\isacharsemicolon}}\isanewline

\ \ {\isaliteral{28}{\isacharparenleft}}{\isaliteral{2A}{\isacharasterisk}}{\isaliteral{2D}{\isacharminus}}\ real\ {\isaliteral{2A}{\isacharasterisk}}{\isaliteral{29}{\isacharparenright}}\isanewline

\ \ term{\isadigit{2}}str\ t{\isaliteral{3B}{\isacharsemicolon}}\isanewline

{\isaliteral{2A7D}{\isacharverbatimclose}}\isanewline

\isacommand{ML}\isamarkupfalse%

\ {\isaliteral{7B2A}{\isacharverbatimopen}}\ terms{\isadigit{2}}str\ {\isaliteral{28}{\isacharparenleft}}asm{\isadigit{1}}\ {\isaliteral{40}{\isacharat}}\ asm{\isadigit{2}}\ {\isaliteral{40}{\isacharat}}\ asm{\isadigit{3}}{\isaliteral{29}{\isacharparenright}}{\isaliteral{3B}{\isacharsemicolon}}\ {\isaliteral{2A7D}{\isacharverbatimclose}}%

\endisatagML

{\isafoldML}%

%

\isadelimML

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\endisadelimML

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\isamarkupsection{Prepare Steps for CTP-based programming Language\label{sec:prepstep}%

}

\isamarkuptrue%

%

\begin{isamarkuptext}%

\par \noindent The following sections are challanging with the CTP-based 

      possibilities of building the programm. The goal is realized in 

      Section~\ref{spec-meth} and Section~\ref{prog-steps}.

      \par The reader is advised to jump between the subsequent subsections and 

      the respective steps in Section~\ref{prog-steps}. By comparing 

      Section~\ref{sec:calc:ztrans} the calculation can be comprehended step 

      by step.%

\end{isamarkuptext}%

\isamarkuptrue%

%

\isamarkupsubsection{Prepare Expression\label{prep-expr}%

}

\isamarkuptrue%

%

\begin{isamarkuptext}%

\noindent We try two different notations and check which of them 

       isabelle can handle best.%

\end{isamarkuptext}%

\isamarkuptrue%

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\isadelimML

%

\endisadelimML

%

\isatagML

\isacommand{ML}\isamarkupfalse%

\ {\isaliteral{7B2A}{\isacharverbatimopen}}\isanewline

\ \ val\ ctxt\ {\isaliteral{3D}{\isacharequal}}\ ProofContext{\isaliteral{2E}{\isachardot}}init{\isaliteral{5F}{\isacharunderscore}}global\ %

\isaantiq

theory\ Isac{}%

\endisaantiq

{\isaliteral{3B}{\isacharsemicolon}}\isanewline

\ \ val\ ctxt\ {\isaliteral{3D}{\isacharequal}}\ declare{\isaliteral{5F}{\isacharunderscore}}constraints{\isaliteral{27}{\isacharprime}}\ {\isaliteral{5B}{\isacharbrackleft}}%

\isaantiq

term\ {\isaliteral{22}{\isachardoublequote}}z{\isaliteral{3A}{\isacharcolon}}{\isaliteral{3A}{\isacharcolon}}real{\isaliteral{22}{\isachardoublequote}}{}%

\endisaantiq

{\isaliteral{5D}{\isacharbrackright}}\ ctxt{\isaliteral{3B}{\isacharsemicolon}}\isanewline

\isanewline

\ \ val\ SOME\ fun{\isadigit{1}}\ {\isaliteral{3D}{\isacharequal}}\ \isanewline

\ \ \ \ parseNEW\ ctxt\ {\isaliteral{22}{\isachardoublequote}}X\ z\ {\isaliteral{3D}{\isacharequal}}\ {\isadigit{3}}\ {\isaliteral{2F}{\isacharslash}}\ {\isaliteral{28}{\isacharparenleft}}z\ {\isaliteral{2D}{\isacharminus}}\ {\isadigit{1}}{\isaliteral{2F}{\isacharslash}}{\isadigit{4}}\ {\isaliteral{2B}{\isacharplus}}\ {\isaliteral{2D}{\isacharminus}}{\isadigit{1}}{\isaliteral{2F}{\isacharslash}}{\isadigit{8}}\ {\isaliteral{2A}{\isacharasterisk}}\ z\ {\isaliteral{5E}{\isacharcircum}}{\isaliteral{5E}{\isacharcircum}}{\isaliteral{5E}{\isacharcircum}}\ {\isaliteral{2D}{\isacharminus}}{\isadigit{1}}{\isaliteral{29}{\isacharparenright}}{\isaliteral{22}{\isachardoublequote}}{\isaliteral{3B}{\isacharsemicolon}}\ term{\isadigit{2}}str\ fun{\isadigit{1}}{\isaliteral{3B}{\isacharsemicolon}}\isanewline

\ \ val\ SOME\ fun{\isadigit{1}}{\isaliteral{27}{\isacharprime}}\ {\isaliteral{3D}{\isacharequal}}\ \isanewline

\ \ \ \ parseNEW\ ctxt\ {\isaliteral{22}{\isachardoublequote}}X\ z\ {\isaliteral{3D}{\isacharequal}}\ {\isadigit{3}}\ {\isaliteral{2F}{\isacharslash}}\ {\isaliteral{28}{\isacharparenleft}}z\ {\isaliteral{2D}{\isacharminus}}\ {\isadigit{1}}{\isaliteral{2F}{\isacharslash}}{\isadigit{4}}\ {\isaliteral{2B}{\isacharplus}}\ {\isaliteral{2D}{\isacharminus}}{\isadigit{1}}{\isaliteral{2F}{\isacharslash}}{\isadigit{8}}\ {\isaliteral{2A}{\isacharasterisk}}\ {\isaliteral{28}{\isacharparenleft}}{\isadigit{1}}{\isaliteral{2F}{\isacharslash}}z{\isaliteral{29}{\isacharparenright}}{\isaliteral{29}{\isacharparenright}}{\isaliteral{22}{\isachardoublequote}}{\isaliteral{3B}{\isacharsemicolon}}\ term{\isadigit{2}}str\ fun{\isadigit{1}}{\isaliteral{27}{\isacharprime}}{\isaliteral{3B}{\isacharsemicolon}}\isanewline

{\isaliteral{2A7D}{\isacharverbatimclose}}%

\endisatagML

{\isafoldML}%

%

\isadelimML

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\endisadelimML

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\isamarkupsubsubsection{Prepare Numerator and Denominator%

}

\isamarkuptrue%

%

\begin{isamarkuptext}%

\noindent The partial fraction decomposion is only possible ig we

       get the bound variable out of the numerator. Therefor we divide

       the expression by $z$. Follow up the Calculation at 

       Section~\ref{sec:calc:ztrans} line number 02.%

\end{isamarkuptext}%

\isamarkuptrue%

\isacommand{axiomatization}\isamarkupfalse%

\ \isakeyword{where}\isanewline

\ \ ruleZY{\isaliteral{3A}{\isacharcolon}}\ {\isaliteral{22}{\isachardoublequoteopen}}{\isaliteral{28}{\isacharparenleft}}X\ z\ {\isaliteral{3D}{\isacharequal}}\ a\ {\isaliteral{2F}{\isacharslash}}\ b{\isaliteral{29}{\isacharparenright}}\ {\isaliteral{3D}{\isacharequal}}\ {\isaliteral{28}{\isacharparenleft}}X{\isaliteral{27}{\isacharprime}}\ z\ {\isaliteral{3D}{\isacharequal}}\ a\ {\isaliteral{2F}{\isacharslash}}\ {\isaliteral{28}{\isacharparenleft}}z\ {\isaliteral{2A}{\isacharasterisk}}\ b{\isaliteral{29}{\isacharparenright}}{\isaliteral{29}{\isacharparenright}}{\isaliteral{22}{\isachardoublequoteclose}}\isanewline

%

\isadelimML

\isanewline

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\endisadelimML

%

\isatagML

\isacommand{ML}\isamarkupfalse%

\ {\isaliteral{7B2A}{\isacharverbatimopen}}\isanewline

\ \ val\ {\isaliteral{28}{\isacharparenleft}}thy{\isaliteral{2C}{\isacharcomma}}\ ro{\isaliteral{2C}{\isacharcomma}}\ er{\isaliteral{29}{\isacharparenright}}\ {\isaliteral{3D}{\isacharequal}}\ {\isaliteral{28}{\isacharparenleft}}%

\isaantiq

theory\ Isac{}%

\endisaantiq

{\isaliteral{2C}{\isacharcomma}}\ tless{\isaliteral{5F}{\isacharunderscore}}true{\isaliteral{2C}{\isacharcomma}}\ eval{\isaliteral{5F}{\isacharunderscore}}rls{\isaliteral{29}{\isacharparenright}}{\isaliteral{3B}{\isacharsemicolon}}\isanewline

\ \ val\ SOME\ {\isaliteral{28}{\isacharparenleft}}fun{\isadigit{2}}{\isaliteral{2C}{\isacharcomma}}\ asm{\isadigit{1}}{\isaliteral{29}{\isacharparenright}}\ {\isaliteral{3D}{\isacharequal}}\ \isanewline

\ \ \ \ rewrite{\isaliteral{5F}{\isacharunderscore}}\ thy\ ro\ er\ true\ \ %

\isaantiq

thm\ ruleZY{}%

\endisaantiq

\ fun{\isadigit{1}}{\isaliteral{3B}{\isacharsemicolon}}\ term{\isadigit{2}}str\ fun{\isadigit{2}}{\isaliteral{3B}{\isacharsemicolon}}\isanewline

\ \ val\ SOME\ {\isaliteral{28}{\isacharparenleft}}fun{\isadigit{2}}{\isaliteral{27}{\isacharprime}}{\isaliteral{2C}{\isacharcomma}}\ asm{\isadigit{1}}{\isaliteral{29}{\isacharparenright}}\ {\isaliteral{3D}{\isacharequal}}\ \isanewline

\ \ \ \ rewrite{\isaliteral{5F}{\isacharunderscore}}\ thy\ ro\ er\ true\ \ %

\isaantiq

thm\ ruleZY{}%

\endisaantiq

\ fun{\isadigit{1}}{\isaliteral{27}{\isacharprime}}{\isaliteral{3B}{\isacharsemicolon}}\ term{\isadigit{2}}str\ fun{\isadigit{2}}{\isaliteral{27}{\isacharprime}}{\isaliteral{3B}{\isacharsemicolon}}\isanewline

\isanewline

\ \ val\ SOME\ {\isaliteral{28}{\isacharparenleft}}fun{\isadigit{3}}{\isaliteral{2C}{\isacharcomma}}{\isaliteral{5F}{\isacharunderscore}}{\isaliteral{29}{\isacharparenright}}\ {\isaliteral{3D}{\isacharequal}}\ \isanewline

\ \ \ \ rewrite{\isaliteral{5F}{\isacharunderscore}}set{\isaliteral{5F}{\isacharunderscore}}\ %

\isaantiq

theory\ Isac{}%

\endisaantiq

\ false\ norm{\isaliteral{5F}{\isacharunderscore}}Rational\ fun{\isadigit{2}}{\isaliteral{3B}{\isacharsemicolon}}\isanewline

\ \ term{\isadigit{2}}str\ fun{\isadigit{3}}{\isaliteral{3B}{\isacharsemicolon}}\isanewline

\ \ {\isaliteral{28}{\isacharparenleft}}{\isaliteral{2A}{\isacharasterisk}}\isanewline

\ \ \ {\isaliteral{2A}{\isacharasterisk}}\ Fails\ on\ x{\isaliteral{5E}{\isacharcircum}}{\isaliteral{5E}{\isacharcircum}}{\isaliteral{5E}{\isacharcircum}}{\isaliteral{28}{\isacharparenleft}}{\isaliteral{2D}{\isacharminus}}{\isadigit{1}}{\isaliteral{29}{\isacharparenright}}\isanewline

\ \ \ {\isaliteral{2A}{\isacharasterisk}}\ We\ solve\ this\ problem\ by\ using\ {\isadigit{1}}{\isaliteral{2F}{\isacharslash}}x\ as\ a\ workaround{\isaliteral{2E}{\isachardot}}\isanewline

\ \ \ {\isaliteral{2A}{\isacharasterisk}}{\isaliteral{29}{\isacharparenright}}\isanewline

\ \ val\ SOME\ {\isaliteral{28}{\isacharparenleft}}fun{\isadigit{3}}{\isaliteral{27}{\isacharprime}}{\isaliteral{2C}{\isacharcomma}}{\isaliteral{5F}{\isacharunderscore}}{\isaliteral{29}{\isacharparenright}}\ {\isaliteral{3D}{\isacharequal}}\ \isanewline

\ \ \ \ rewrite{\isaliteral{5F}{\isacharunderscore}}set{\isaliteral{5F}{\isacharunderscore}}\ %

\isaantiq

theory\ Isac{}%

\endisaantiq

\ false\ norm{\isaliteral{5F}{\isacharunderscore}}Rational\ fun{\isadigit{2}}{\isaliteral{27}{\isacharprime}}{\isaliteral{3B}{\isacharsemicolon}}\isanewline

\ \ term{\isadigit{2}}str\ fun{\isadigit{3}}{\isaliteral{27}{\isacharprime}}{\isaliteral{3B}{\isacharsemicolon}}\isanewline

\ \ {\isaliteral{28}{\isacharparenleft}}{\isaliteral{2A}{\isacharasterisk}}\isanewline

\ \ \ {\isaliteral{2A}{\isacharasterisk}}\ OK\ {\isaliteral{2D}{\isacharminus}}\ workaround{\isaliteral{21}{\isacharbang}}\isanewline

\ \ \ {\isaliteral{2A}{\isacharasterisk}}{\isaliteral{29}{\isacharparenright}}\isanewline

{\isaliteral{2A7D}{\isacharverbatimclose}}%

\endisatagML

{\isafoldML}%

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\isadelimML

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\endisadelimML

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\isamarkupsubsubsection{Get the Argument of the Expression X'%

}

\isamarkuptrue%

%

\begin{isamarkuptext}%

\noindent We use \texttt{grep} for finding possibilities how we can

       extract the bound variable in the expression. \ttfamily Atools.thy, 

       Tools.thy \normalfont contain general utilities: \ttfamily 

       eval\_argument\_in, eval\_rhs, eval\_lhs,\ldots \normalfont

       \ttfamily grep -r "fun eva\_" * \normalfont shows all functions 

       witch can be used in a script. Lookup this files how to build 

       and handle such functions.

       \par The next section shows how to introduce such a function.%

\end{isamarkuptext}%

\isamarkuptrue%

%

\isamarkupsubsubsection{Decompose the Given Term Into lhs and rhs\footnote{Note:

               lhs means \em Left Hand Side \normalfont and rhs means 

               \em Right Hand Side \normalfont and indicates the left or 

               the right part of an equation.}%

}

\isamarkuptrue%

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\isadelimML

%

\endisadelimML

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\isatagML

\isacommand{ML}\isamarkupfalse%

\ {\isaliteral{7B2A}{\isacharverbatimopen}}\isanewline

\ \ val\ {\isaliteral{28}{\isacharparenleft}}{\isaliteral{5F}{\isacharunderscore}}{\isaliteral{2C}{\isacharcomma}}\ expr{\isaliteral{29}{\isacharparenright}}\ {\isaliteral{3D}{\isacharequal}}\ HOLogic{\isaliteral{2E}{\isachardot}}dest{\isaliteral{5F}{\isacharunderscore}}eq\ fun{\isadigit{3}}{\isaliteral{27}{\isacharprime}}{\isaliteral{3B}{\isacharsemicolon}}\ term{\isadigit{2}}str\ expr{\isaliteral{3B}{\isacharsemicolon}}\isanewline

\ \ val\ {\isaliteral{28}{\isacharparenleft}}{\isaliteral{5F}{\isacharunderscore}}{\isaliteral{2C}{\isacharcomma}}\ denom{\isaliteral{29}{\isacharparenright}}\ {\isaliteral{3D}{\isacharequal}}\ \isanewline

\ \ \ \ HOLogic{\isaliteral{2E}{\isachardot}}dest{\isaliteral{5F}{\isacharunderscore}}bin\ {\isaliteral{22}{\isachardoublequote}}Rings{\isaliteral{2E}{\isachardot}}inverse{\isaliteral{5F}{\isacharunderscore}}class{\isaliteral{2E}{\isachardot}}divide{\isaliteral{22}{\isachardoublequote}}\ {\isaliteral{28}{\isacharparenleft}}type{\isaliteral{5F}{\isacharunderscore}}of\ expr{\isaliteral{29}{\isacharparenright}}\ expr{\isaliteral{3B}{\isacharsemicolon}}\isanewline

\ \ term{\isadigit{2}}str\ denom\ {\isaliteral{3D}{\isacharequal}}\ {\isaliteral{22}{\isachardoublequote}}{\isaliteral{2D}{\isacharminus}}{\isadigit{1}}\ {\isaliteral{2B}{\isacharplus}}\ {\isaliteral{2D}{\isacharminus}}{\isadigit{2}}\ {\isaliteral{2A}{\isacharasterisk}}\ z\ {\isaliteral{2B}{\isacharplus}}\ {\isadigit{8}}\ {\isaliteral{2A}{\isacharasterisk}}\ z\ {\isaliteral{5E}{\isacharcircum}}{\isaliteral{5E}{\isacharcircum}}{\isaliteral{5E}{\isacharcircum}}\ {\isadigit{2}}{\isaliteral{22}{\isachardoublequote}}{\isaliteral{3B}{\isacharsemicolon}}\isanewline

{\isaliteral{2A7D}{\isacharverbatimclose}}%

\endisatagML

{\isafoldML}%

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\isadelimML

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\endisadelimML

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\begin{isamarkuptext}%

\noindent We have rhs in the Script language, but we need a function 

       which gets the denominator of a fraction.%

\end{isamarkuptext}%

\isamarkuptrue%

%

\isamarkupsubsubsection{Get the Denominator and Numerator out of a Fraction%

}

\isamarkuptrue%

%

\begin{isamarkuptext}%

\noindent The selv written functions in e.g. \texttt{get\_denominator}

       should become a constant for the isabelle parser:%

\end{isamarkuptext}%

\isamarkuptrue%

\isacommand{consts}\isamarkupfalse%

\isanewline

\ \ get{\isaliteral{5F}{\isacharunderscore}}denominator\ {\isaliteral{3A}{\isacharcolon}}{\isaliteral{3A}{\isacharcolon}}\ {\isaliteral{22}{\isachardoublequoteopen}}real\ {\isaliteral{3D}{\isacharequal}}{\isaliteral{3E}{\isachargreater}}\ real{\isaliteral{22}{\isachardoublequoteclose}}\isanewline

\ \ get{\isaliteral{5F}{\isacharunderscore}}numerator\ {\isaliteral{3A}{\isacharcolon}}{\isaliteral{3A}{\isacharcolon}}\ {\isaliteral{22}{\isachardoublequoteopen}}real\ {\isaliteral{3D}{\isacharequal}}{\isaliteral{3E}{\isachargreater}}\ real{\isaliteral{22}{\isachardoublequoteclose}}%

\begin{isamarkuptext}%

\noindent With the above definition we run into problems when we parse

        the Script \texttt{InverseZTransform}. This leads to \em ambiguous

        parse trees. \normalfont We avoid this by moving the definition

        to \ttfamily Rational.thy \normalfont and re-building {\sisac}.

        \par \noindent ATTENTION: From now on \ttfamily 

        Build\_Inverse\_Z\_Transform \normalfont mimics a build from scratch;

        it only works due to re-building {\sisac} several times (indicated 

        explicityl).%

\end{isamarkuptext}%

\isamarkuptrue%

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\isadelimML

%

\endisadelimML

%

\isatagML

\isacommand{ML}\isamarkupfalse%

\ {\isaliteral{7B2A}{\isacharverbatimopen}}\isanewline

{\isaliteral{28}{\isacharparenleft}}{\isaliteral{2A}{\isacharasterisk}}\isanewline

\ {\isaliteral{2A}{\isacharasterisk}}{\isaliteral{28}{\isacharparenleft}}{\isaliteral{22}{\isachardoublequote}}get{\isaliteral{5F}{\isacharunderscore}}denominator{\isaliteral{22}{\isachardoublequote}}{\isaliteral{2C}{\isacharcomma}}\isanewline

\ {\isaliteral{2A}{\isacharasterisk}}\ \ {\isaliteral{28}{\isacharparenleft}}{\isaliteral{22}{\isachardoublequote}}Rational{\isaliteral{2E}{\isachardot}}get{\isaliteral{5F}{\isacharunderscore}}denominator{\isaliteral{22}{\isachardoublequote}}{\isaliteral{2C}{\isacharcomma}}\ eval{\isaliteral{5F}{\isacharunderscore}}get{\isaliteral{5F}{\isacharunderscore}}denominator\ {\isaliteral{22}{\isachardoublequote}}{\isaliteral{22}{\isachardoublequote}}{\isaliteral{29}{\isacharparenright}}{\isaliteral{29}{\isacharparenright}}\isanewline

\ {\isaliteral{2A}{\isacharasterisk}}{\isaliteral{29}{\isacharparenright}}\isanewline

fun\ eval{\isaliteral{5F}{\isacharunderscore}}get{\isaliteral{5F}{\isacharunderscore}}denominator\ {\isaliteral{28}{\isacharparenleft}}thmid{\isaliteral{3A}{\isacharcolon}}string{\isaliteral{29}{\isacharparenright}}\ {\isaliteral{5F}{\isacharunderscore}}\ \isanewline

		\ \ \ \ \ \ {\isaliteral{28}{\isacharparenleft}}t\ as\ Const\ {\isaliteral{28}{\isacharparenleft}}{\isaliteral{22}{\isachardoublequote}}Rational{\isaliteral{2E}{\isachardot}}get{\isaliteral{5F}{\isacharunderscore}}denominator{\isaliteral{22}{\isachardoublequote}}{\isaliteral{2C}{\isacharcomma}}\ {\isaliteral{5F}{\isacharunderscore}}{\isaliteral{29}{\isacharparenright}}\ {\isaliteral{24}{\isachardollar}}\isanewline

\ \ \ \ \ \ \ \ \ \ \ \ \ \ {\isaliteral{28}{\isacharparenleft}}Const\ {\isaliteral{28}{\isacharparenleft}}{\isaliteral{22}{\isachardoublequote}}Rings{\isaliteral{2E}{\isachardot}}inverse{\isaliteral{5F}{\isacharunderscore}}class{\isaliteral{2E}{\isachardot}}divide{\isaliteral{22}{\isachardoublequote}}{\isaliteral{2C}{\isacharcomma}}\ {\isaliteral{5F}{\isacharunderscore}}{\isaliteral{29}{\isacharparenright}}\ {\isaliteral{24}{\isachardollar}}num\ \isanewline

\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ {\isaliteral{24}{\isachardollar}}denom{\isaliteral{29}{\isacharparenright}}{\isaliteral{29}{\isacharparenright}}\ thy\ {\isaliteral{3D}{\isacharequal}}\ \isanewline

\ \ \ \ \ \ \ \ SOME\ {\isaliteral{28}{\isacharparenleft}}mk{\isaliteral{5F}{\isacharunderscore}}thmid\ thmid\ {\isaliteral{22}{\isachardoublequote}}{\isaliteral{22}{\isachardoublequote}}\ \isanewline

\ \ \ \ \ \ \ \ \ \ \ \ {\isaliteral{28}{\isacharparenleft}}Print{\isaliteral{5F}{\isacharunderscore}}Mode{\isaliteral{2E}{\isachardot}}setmp\ {\isaliteral{5B}{\isacharbrackleft}}{\isaliteral{5D}{\isacharbrackright}}\ \isanewline

\ \ \ \ \ \ \ \ \ \ \ \ \ \ {\isaliteral{28}{\isacharparenleft}}Syntax{\isaliteral{2E}{\isachardot}}string{\isaliteral{5F}{\isacharunderscore}}of{\isaliteral{5F}{\isacharunderscore}}term\ {\isaliteral{28}{\isacharparenleft}}thy{\isadigit{2}}ctxt\ thy{\isaliteral{29}{\isacharparenright}}{\isaliteral{29}{\isacharparenright}}\ denom{\isaliteral{29}{\isacharparenright}}\ {\isaliteral{22}{\isachardoublequote}}{\isaliteral{22}{\isachardoublequote}}{\isaliteral{2C}{\isacharcomma}}\ \isanewline

	\ \ \ \ \ \ \ \ \ \ Trueprop\ {\isaliteral{24}{\isachardollar}}\ {\isaliteral{28}{\isacharparenleft}}mk{\isaliteral{5F}{\isacharunderscore}}equality\ {\isaliteral{28}{\isacharparenleft}}t{\isaliteral{2C}{\isacharcomma}}\ denom{\isaliteral{29}{\isacharparenright}}{\isaliteral{29}{\isacharparenright}}{\isaliteral{29}{\isacharparenright}}\isanewline

\ \ {\isaliteral{7C}{\isacharbar}}\ eval{\isaliteral{5F}{\isacharunderscore}}get{\isaliteral{5F}{\isacharunderscore}}denominator\ {\isaliteral{5F}{\isacharunderscore}}\ {\isaliteral{5F}{\isacharunderscore}}\ {\isaliteral{5F}{\isacharunderscore}}\ {\isaliteral{5F}{\isacharunderscore}}\ {\isaliteral{3D}{\isacharequal}}\ NONE{\isaliteral{3B}{\isacharsemicolon}}\ \isanewline

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\begin{isamarkuptext}%

\noindent For the tests of \ttfamily eval\_get\_denominator \normalfont

        see \ttfamily test/Knowledge/rational.sml\normalfont%

\end{isamarkuptext}%

\isamarkuptrue%

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\begin{isamarkuptext}%

\noindent \ttfamily get\_numerator \normalfont should also become a

        constant for the isabelle parser, follow up the \texttt{const}

        decleration above.%

\end{isamarkuptext}%

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\ {\isaliteral{7B2A}{\isacharverbatimopen}}\isanewline

{\isaliteral{28}{\isacharparenleft}}{\isaliteral{2A}{\isacharasterisk}}\isanewline

\ {\isaliteral{2A}{\isacharasterisk}}{\isaliteral{28}{\isacharparenleft}}{\isaliteral{22}{\isachardoublequote}}get{\isaliteral{5F}{\isacharunderscore}}numerator{\isaliteral{22}{\isachardoublequote}}{\isaliteral{2C}{\isacharcomma}}\isanewline

\ {\isaliteral{2A}{\isacharasterisk}}\ \ {\isaliteral{28}{\isacharparenleft}}{\isaliteral{22}{\isachardoublequote}}Rational{\isaliteral{2E}{\isachardot}}get{\isaliteral{5F}{\isacharunderscore}}numerator{\isaliteral{22}{\isachardoublequote}}{\isaliteral{2C}{\isacharcomma}}\ eval{\isaliteral{5F}{\isacharunderscore}}get{\isaliteral{5F}{\isacharunderscore}}numerator\ {\isaliteral{22}{\isachardoublequote}}{\isaliteral{22}{\isachardoublequote}}{\isaliteral{29}{\isacharparenright}}{\isaliteral{29}{\isacharparenright}}\isanewline

\ {\isaliteral{2A}{\isacharasterisk}}{\isaliteral{29}{\isacharparenright}}\isanewline

fun\ eval{\isaliteral{5F}{\isacharunderscore}}get{\isaliteral{5F}{\isacharunderscore}}numerator\ {\isaliteral{28}{\isacharparenleft}}thmid{\isaliteral{3A}{\isacharcolon}}string{\isaliteral{29}{\isacharparenright}}\ {\isaliteral{5F}{\isacharunderscore}}\ \isanewline

		\ \ \ \ \ \ {\isaliteral{28}{\isacharparenleft}}t\ as\ Const\ {\isaliteral{28}{\isacharparenleft}}{\isaliteral{22}{\isachardoublequote}}Rational{\isaliteral{2E}{\isachardot}}get{\isaliteral{5F}{\isacharunderscore}}numerator{\isaliteral{22}{\isachardoublequote}}{\isaliteral{2C}{\isacharcomma}}\ {\isaliteral{5F}{\isacharunderscore}}{\isaliteral{29}{\isacharparenright}}\ {\isaliteral{24}{\isachardollar}}\isanewline

\ \ \ \ \ \ \ \ \ \ \ \ \ \ {\isaliteral{28}{\isacharparenleft}}Const\ {\isaliteral{28}{\isacharparenleft}}{\isaliteral{22}{\isachardoublequote}}Rings{\isaliteral{2E}{\isachardot}}inverse{\isaliteral{5F}{\isacharunderscore}}class{\isaliteral{2E}{\isachardot}}divide{\isaliteral{22}{\isachardoublequote}}{\isaliteral{2C}{\isacharcomma}}\ {\isaliteral{5F}{\isacharunderscore}}{\isaliteral{29}{\isacharparenright}}\ {\isaliteral{24}{\isachardollar}}num\isanewline

\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ {\isaliteral{24}{\isachardollar}}denom\ {\isaliteral{29}{\isacharparenright}}{\isaliteral{29}{\isacharparenright}}\ thy\ {\isaliteral{3D}{\isacharequal}}\ \isanewline

\ \ \ \ \ \ \ \ SOME\ {\isaliteral{28}{\isacharparenleft}}mk{\isaliteral{5F}{\isacharunderscore}}thmid\ thmid\ {\isaliteral{22}{\isachardoublequote}}{\isaliteral{22}{\isachardoublequote}}\ \isanewline

\ \ \ \ \ \ \ \ \ \ \ \ {\isaliteral{28}{\isacharparenleft}}Print{\isaliteral{5F}{\isacharunderscore}}Mode{\isaliteral{2E}{\isachardot}}setmp\ {\isaliteral{5B}{\isacharbrackleft}}{\isaliteral{5D}{\isacharbrackright}}\ \isanewline

\ \ \ \ \ \ \ \ \ \ \ \ \ \ {\isaliteral{28}{\isacharparenleft}}Syntax{\isaliteral{2E}{\isachardot}}string{\isaliteral{5F}{\isacharunderscore}}of{\isaliteral{5F}{\isacharunderscore}}term\ {\isaliteral{28}{\isacharparenleft}}thy{\isadigit{2}}ctxt\ thy{\isaliteral{29}{\isacharparenright}}{\isaliteral{29}{\isacharparenright}}\ num{\isaliteral{29}{\isacharparenright}}\ {\isaliteral{22}{\isachardoublequote}}{\isaliteral{22}{\isachardoublequote}}{\isaliteral{2C}{\isacharcomma}}\ \isanewline

	\ \ \ \ \ \ \ \ \ \ Trueprop\ {\isaliteral{24}{\isachardollar}}\ {\isaliteral{28}{\isacharparenleft}}mk{\isaliteral{5F}{\isacharunderscore}}equality\ {\isaliteral{28}{\isacharparenleft}}t{\isaliteral{2C}{\isacharcomma}}\ num{\isaliteral{29}{\isacharparenright}}{\isaliteral{29}{\isacharparenright}}{\isaliteral{29}{\isacharparenright}}\isanewline

\ \ {\isaliteral{7C}{\isacharbar}}\ eval{\isaliteral{5F}{\isacharunderscore}}get{\isaliteral{5F}{\isacharunderscore}}numerator\ {\isaliteral{5F}{\isacharunderscore}}\ {\isaliteral{5F}{\isacharunderscore}}\ {\isaliteral{5F}{\isacharunderscore}}\ {\isaliteral{5F}{\isacharunderscore}}\ {\isaliteral{3D}{\isacharequal}}\ NONE{\isaliteral{3B}{\isacharsemicolon}}\ \isanewline

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\begin{isamarkuptext}%

\noindent We discovered severell problems by implementing the 

       \ttfamily get\_numerator \normalfont function. Remember when 

       putting new functions to {\sisac}, put them in a thy file and rebuild 

       {\sisac}, also put them in the ruleset for the script!%

\end{isamarkuptext}%

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\isamarkupsubsection{Solve Equation\label{sec:solveq}%

}

\isamarkuptrue%

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\begin{isamarkuptext}%

\noindent We have to find the zeros of the term, therefor we use our

       \ttfamily get\_denominator \normalfont function from the step before

       and try to solve the second order eqeuation. (Follow up the Calculation

       in Section~\ref{sec:calc:ztrans} Subproblem 2) Note: This type of

       equation is too general for the present program.

       \par We know that this equation can be categorized as \em univariate

       equation \normalfont and solved with the functions {\sisac} provides

       for this equation type. Later on {\sisac} should determine the type

       of the given equation self.%

\end{isamarkuptext}%

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\ {\isaliteral{7B2A}{\isacharverbatimopen}}\isanewline

\ \ val\ denominator\ {\isaliteral{3D}{\isacharequal}}\ parseNEW\ ctxt\ {\isaliteral{22}{\isachardoublequote}}z{\isaliteral{5E}{\isacharcircum}}{\isaliteral{5E}{\isacharcircum}}{\isaliteral{5E}{\isacharcircum}}{\isadigit{2}}\ {\isaliteral{2D}{\isacharminus}}\ {\isadigit{1}}{\isaliteral{2F}{\isacharslash}}{\isadigit{4}}{\isaliteral{2A}{\isacharasterisk}}z\ {\isaliteral{2D}{\isacharminus}}\ {\isadigit{1}}{\isaliteral{2F}{\isacharslash}}{\isadigit{8}}\ {\isaliteral{3D}{\isacharequal}}\ {\isadigit{0}}{\isaliteral{22}{\isachardoublequote}}{\isaliteral{3B}{\isacharsemicolon}}\isanewline

\ \ val\ fmz\ {\isaliteral{3D}{\isacharequal}}\ {\isaliteral{5B}{\isacharbrackleft}}{\isaliteral{22}{\isachardoublequote}}equality\ {\isaliteral{28}{\isacharparenleft}}z{\isaliteral{5E}{\isacharcircum}}{\isaliteral{5E}{\isacharcircum}}{\isaliteral{5E}{\isacharcircum}}{\isadigit{2}}\ {\isaliteral{2D}{\isacharminus}}\ {\isadigit{1}}{\isaliteral{2F}{\isacharslash}}{\isadigit{4}}{\isaliteral{2A}{\isacharasterisk}}z\ {\isaliteral{2D}{\isacharminus}}\ {\isadigit{1}}{\isaliteral{2F}{\isacharslash}}{\isadigit{8}}\ {\isaliteral{3D}{\isacharequal}}\ {\isaliteral{28}{\isacharparenleft}}{\isadigit{0}}{\isaliteral{3A}{\isacharcolon}}{\isaliteral{3A}{\isacharcolon}}real{\isaliteral{29}{\isacharparenright}}{\isaliteral{29}{\isacharparenright}}{\isaliteral{22}{\isachardoublequote}}{\isaliteral{2C}{\isacharcomma}}\isanewline

\ \ \ \ \ \ \ \ \ \ \ \ \ {\isaliteral{22}{\isachardoublequote}}solveFor\ z{\isaliteral{22}{\isachardoublequote}}{\isaliteral{2C}{\isacharcomma}}\isanewline

\ \ \ \ \ \ \ \ \ \ \ \ \ {\isaliteral{22}{\isachardoublequote}}solutions\ L{\isaliteral{22}{\isachardoublequote}}{\isaliteral{5D}{\isacharbrackright}}{\isaliteral{3B}{\isacharsemicolon}}\isanewline

\ \ val\ {\isaliteral{28}{\isacharparenleft}}dI{\isaliteral{27}{\isacharprime}}{\isaliteral{2C}{\isacharcomma}}pI{\isaliteral{27}{\isacharprime}}{\isaliteral{2C}{\isacharcomma}}mI{\isaliteral{27}{\isacharprime}}{\isaliteral{29}{\isacharparenright}}\ {\isaliteral{3D}{\isacharequal}}{\isaliteral{28}{\isacharparenleft}}{\isaliteral{22}{\isachardoublequote}}Isac{\isaliteral{22}{\isachardoublequote}}{\isaliteral{2C}{\isacharcomma}}\ {\isaliteral{5B}{\isacharbrackleft}}{\isaliteral{22}{\isachardoublequote}}univariate{\isaliteral{22}{\isachardoublequote}}{\isaliteral{2C}{\isacharcomma}}{\isaliteral{22}{\isachardoublequote}}equation{\isaliteral{22}{\isachardoublequote}}{\isaliteral{5D}{\isacharbrackright}}{\isaliteral{2C}{\isacharcomma}}\ {\isaliteral{5B}{\isacharbrackleft}}{\isaliteral{22}{\isachardoublequote}}no{\isaliteral{5F}{\isacharunderscore}}met{\isaliteral{22}{\isachardoublequote}}{\isaliteral{5D}{\isacharbrackright}}{\isaliteral{29}{\isacharparenright}}{\isaliteral{3B}{\isacharsemicolon}}\isanewline

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\begin{isamarkuptext}%

\noindent Check if the given equation matches the specification of this

        quation type.%

\end{isamarkuptext}%

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\ {\isaliteral{7B2A}{\isacharverbatimopen}}\isanewline

\ \ match{\isaliteral{5F}{\isacharunderscore}}pbl\ fmz\ {\isaliteral{28}{\isacharparenleft}}get{\isaliteral{5F}{\isacharunderscore}}pbt\ {\isaliteral{5B}{\isacharbrackleft}}{\isaliteral{22}{\isachardoublequote}}univariate{\isaliteral{22}{\isachardoublequote}}{\isaliteral{2C}{\isacharcomma}}{\isaliteral{22}{\isachardoublequote}}equation{\isaliteral{22}{\isachardoublequote}}{\isaliteral{5D}{\isacharbrackright}}{\isaliteral{29}{\isacharparenright}}{\isaliteral{3B}{\isacharsemicolon}}\isanewline

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\begin{isamarkuptext}%

\noindent We switch up to the {\sisac} Context and try to solve the 

       equation with a more specific type definition.%

\end{isamarkuptext}%

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\ \ Context{\isaliteral{2E}{\isachardot}}theory{\isaliteral{5F}{\isacharunderscore}}name\ thy\ {\isaliteral{3D}{\isacharequal}}\ {\isaliteral{22}{\isachardoublequote}}Isac{\isaliteral{22}{\isachardoublequote}}{\isaliteral{3B}{\isacharsemicolon}}\isanewline

\ \ val\ denominator\ {\isaliteral{3D}{\isacharequal}}\ parseNEW\ ctxt\ {\isaliteral{22}{\isachardoublequote}}{\isaliteral{2D}{\isacharminus}}{\isadigit{1}}\ {\isaliteral{2B}{\isacharplus}}\ {\isaliteral{2D}{\isacharminus}}{\isadigit{2}}\ {\isaliteral{2A}{\isacharasterisk}}\ z\ {\isaliteral{2B}{\isacharplus}}\ {\isadigit{8}}\ {\isaliteral{2A}{\isacharasterisk}}\ z\ {\isaliteral{5E}{\isacharcircum}}{\isaliteral{5E}{\isacharcircum}}{\isaliteral{5E}{\isacharcircum}}\ {\isadigit{2}}\ {\isaliteral{3D}{\isacharequal}}\ {\isadigit{0}}{\isaliteral{22}{\isachardoublequote}}{\isaliteral{3B}{\isacharsemicolon}}\isanewline

\ \ val\ fmz\ {\isaliteral{3D}{\isacharequal}}\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ {\isaliteral{28}{\isacharparenleft}}{\isaliteral{2A}{\isacharasterisk}}specification{\isaliteral{2A}{\isacharasterisk}}{\isaliteral{29}{\isacharparenright}}\isanewline

\ \ \ \ {\isaliteral{5B}{\isacharbrackleft}}{\isaliteral{22}{\isachardoublequote}}equality\ {\isaliteral{28}{\isacharparenleft}}{\isaliteral{2D}{\isacharminus}}{\isadigit{1}}\ {\isaliteral{2B}{\isacharplus}}\ {\isaliteral{2D}{\isacharminus}}{\isadigit{2}}\ {\isaliteral{2A}{\isacharasterisk}}\ z\ {\isaliteral{2B}{\isacharplus}}\ {\isadigit{8}}\ {\isaliteral{2A}{\isacharasterisk}}\ z\ {\isaliteral{5E}{\isacharcircum}}{\isaliteral{5E}{\isacharcircum}}{\isaliteral{5E}{\isacharcircum}}\ {\isadigit{2}}\ {\isaliteral{3D}{\isacharequal}}\ {\isaliteral{28}{\isacharparenleft}}{\isadigit{0}}{\isaliteral{3A}{\isacharcolon}}{\isaliteral{3A}{\isacharcolon}}real{\isaliteral{29}{\isacharparenright}}{\isaliteral{29}{\isacharparenright}}{\isaliteral{22}{\isachardoublequote}}{\isaliteral{2C}{\isacharcomma}}{\isaliteral{28}{\isacharparenleft}}{\isaliteral{2A}{\isacharasterisk}}equality{\isaliteral{2A}{\isacharasterisk}}{\isaliteral{29}{\isacharparenright}}\isanewline

\ \ \ \ \ {\isaliteral{22}{\isachardoublequote}}solveFor\ z{\isaliteral{22}{\isachardoublequote}}{\isaliteral{2C}{\isacharcomma}}\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ {\isaliteral{28}{\isacharparenleft}}{\isaliteral{2A}{\isacharasterisk}}bound\ variable{\isaliteral{2A}{\isacharasterisk}}{\isaliteral{29}{\isacharparenright}}\isanewline

\ \ \ \ \ {\isaliteral{22}{\isachardoublequote}}solutions\ L{\isaliteral{22}{\isachardoublequote}}{\isaliteral{5D}{\isacharbrackright}}{\isaliteral{3B}{\isacharsemicolon}}\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ {\isaliteral{28}{\isacharparenleft}}{\isaliteral{2A}{\isacharasterisk}}identifier\ for\isanewline

\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ solution{\isaliteral{2A}{\isacharasterisk}}{\isaliteral{29}{\isacharparenright}}\isanewline

\ \ val\ {\isaliteral{28}{\isacharparenleft}}dI{\isaliteral{27}{\isacharprime}}{\isaliteral{2C}{\isacharcomma}}pI{\isaliteral{27}{\isacharprime}}{\isaliteral{2C}{\isacharcomma}}mI{\isaliteral{27}{\isacharprime}}{\isaliteral{29}{\isacharparenright}}\ {\isaliteral{3D}{\isacharequal}}\isanewline

\ \ \ \ {\isaliteral{28}{\isacharparenleft}}{\isaliteral{22}{\isachardoublequote}}Isac{\isaliteral{22}{\isachardoublequote}}{\isaliteral{2C}{\isacharcomma}}\ \isanewline

\ \ \ \ \ \ {\isaliteral{5B}{\isacharbrackleft}}{\isaliteral{22}{\isachardoublequote}}abcFormula{\isaliteral{22}{\isachardoublequote}}{\isaliteral{2C}{\isacharcomma}}{\isaliteral{22}{\isachardoublequote}}degree{\isaliteral{5F}{\isacharunderscore}}{\isadigit{2}}{\isaliteral{22}{\isachardoublequote}}{\isaliteral{2C}{\isacharcomma}}{\isaliteral{22}{\isachardoublequote}}polynomial{\isaliteral{22}{\isachardoublequote}}{\isaliteral{2C}{\isacharcomma}}{\isaliteral{22}{\isachardoublequote}}univariate{\isaliteral{22}{\isachardoublequote}}{\isaliteral{2C}{\isacharcomma}}{\isaliteral{22}{\isachardoublequote}}equation{\isaliteral{22}{\isachardoublequote}}{\isaliteral{5D}{\isacharbrackright}}{\isaliteral{2C}{\isacharcomma}}\isanewline

\ \ \ \ \ \ {\isaliteral{5B}{\isacharbrackleft}}{\isaliteral{22}{\isachardoublequote}}no{\isaliteral{5F}{\isacharunderscore}}met{\isaliteral{22}{\isachardoublequote}}{\isaliteral{5D}{\isacharbrackright}}{\isaliteral{29}{\isacharparenright}}{\isaliteral{3B}{\isacharsemicolon}}\isanewline

{\isaliteral{2A7D}{\isacharverbatimclose}}%

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\begin{isamarkuptext}%

\noindent Check if the (other) given equation matches the 

        specification of this quation type.%

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\ \ match{\isaliteral{5F}{\isacharunderscore}}pbl\ fmz\ {\isaliteral{28}{\isacharparenleft}}get{\isaliteral{5F}{\isacharunderscore}}pbt\ \isanewline

\ \ \ \ {\isaliteral{5B}{\isacharbrackleft}}{\isaliteral{22}{\isachardoublequote}}abcFormula{\isaliteral{22}{\isachardoublequote}}{\isaliteral{2C}{\isacharcomma}}{\isaliteral{22}{\isachardoublequote}}degree{\isaliteral{5F}{\isacharunderscore}}{\isadigit{2}}{\isaliteral{22}{\isachardoublequote}}{\isaliteral{2C}{\isacharcomma}}{\isaliteral{22}{\isachardoublequote}}polynomial{\isaliteral{22}{\isachardoublequote}}{\isaliteral{2C}{\isacharcomma}}{\isaliteral{22}{\isachardoublequote}}univariate{\isaliteral{22}{\isachardoublequote}}{\isaliteral{2C}{\isacharcomma}}{\isaliteral{22}{\isachardoublequote}}equation{\isaliteral{22}{\isachardoublequote}}{\isaliteral{5D}{\isacharbrackright}}{\isaliteral{29}{\isacharparenright}}{\isaliteral{3B}{\isacharsemicolon}}\isanewline

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\begin{isamarkuptext}%

\noindent We stepwise solve the equation. This is done by the

        use of a so called calc tree seen downwards.%

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\ {\isaliteral{7B2A}{\isacharverbatimopen}}\isanewline

\ \ val\ {\isaliteral{28}{\isacharparenleft}}p{\isaliteral{2C}{\isacharcomma}}{\isaliteral{5F}{\isacharunderscore}}{\isaliteral{2C}{\isacharcomma}}f{\isaliteral{2C}{\isacharcomma}}nxt{\isaliteral{2C}{\isacharcomma}}{\isaliteral{5F}{\isacharunderscore}}{\isaliteral{2C}{\isacharcomma}}pt{\isaliteral{29}{\isacharparenright}}\ {\isaliteral{3D}{\isacharequal}}\ CalcTreeTEST\ {\isaliteral{5B}{\isacharbrackleft}}{\isaliteral{28}{\isacharparenleft}}fmz{\isaliteral{2C}{\isacharcomma}}\ {\isaliteral{28}{\isacharparenleft}}dI{\isaliteral{27}{\isacharprime}}{\isaliteral{2C}{\isacharcomma}}pI{\isaliteral{27}{\isacharprime}}{\isaliteral{2C}{\isacharcomma}}mI{\isaliteral{27}{\isacharprime}}{\isaliteral{29}{\isacharparenright}}{\isaliteral{29}{\isacharparenright}}{\isaliteral{5D}{\isacharbrackright}}{\isaliteral{3B}{\isacharsemicolon}}\isanewline

\ \ val\ {\isaliteral{28}{\isacharparenleft}}p{\isaliteral{2C}{\isacharcomma}}{\isaliteral{5F}{\isacharunderscore}}{\isaliteral{2C}{\isacharcomma}}f{\isaliteral{2C}{\isacharcomma}}nxt{\isaliteral{2C}{\isacharcomma}}{\isaliteral{5F}{\isacharunderscore}}{\isaliteral{2C}{\isacharcomma}}pt{\isaliteral{29}{\isacharparenright}}\ {\isaliteral{3D}{\isacharequal}}\ me\ nxt\ p\ {\isaliteral{5B}{\isacharbrackleft}}{\isaliteral{5D}{\isacharbrackright}}\ pt{\isaliteral{3B}{\isacharsemicolon}}\isanewline

\ \ val\ {\isaliteral{28}{\isacharparenleft}}p{\isaliteral{2C}{\isacharcomma}}{\isaliteral{5F}{\isacharunderscore}}{\isaliteral{2C}{\isacharcomma}}f{\isaliteral{2C}{\isacharcomma}}nxt{\isaliteral{2C}{\isacharcomma}}{\isaliteral{5F}{\isacharunderscore}}{\isaliteral{2C}{\isacharcomma}}pt{\isaliteral{29}{\isacharparenright}}\ {\isaliteral{3D}{\isacharequal}}\ me\ nxt\ p\ {\isaliteral{5B}{\isacharbrackleft}}{\isaliteral{5D}{\isacharbrackright}}\ pt{\isaliteral{3B}{\isacharsemicolon}}\isanewline

\ \ val\ {\isaliteral{28}{\isacharparenleft}}p{\isaliteral{2C}{\isacharcomma}}{\isaliteral{5F}{\isacharunderscore}}{\isaliteral{2C}{\isacharcomma}}f{\isaliteral{2C}{\isacharcomma}}nxt{\isaliteral{2C}{\isacharcomma}}{\isaliteral{5F}{\isacharunderscore}}{\isaliteral{2C}{\isacharcomma}}pt{\isaliteral{29}{\isacharparenright}}\ {\isaliteral{3D}{\isacharequal}}\ me\ nxt\ p\ {\isaliteral{5B}{\isacharbrackleft}}{\isaliteral{5D}{\isacharbrackright}}\ pt{\isaliteral{3B}{\isacharsemicolon}}\isanewline

\ \ val\ {\isaliteral{28}{\isacharparenleft}}p{\isaliteral{2C}{\isacharcomma}}{\isaliteral{5F}{\isacharunderscore}}{\isaliteral{2C}{\isacharcomma}}f{\isaliteral{2C}{\isacharcomma}}nxt{\isaliteral{2C}{\isacharcomma}}{\isaliteral{5F}{\isacharunderscore}}{\isaliteral{2C}{\isacharcomma}}pt{\isaliteral{29}{\isacharparenright}}\ {\isaliteral{3D}{\isacharequal}}\ me\ nxt\ p\ {\isaliteral{5B}{\isacharbrackleft}}{\isaliteral{5D}{\isacharbrackright}}\ pt{\isaliteral{3B}{\isacharsemicolon}}\isanewline

\ \ val\ {\isaliteral{28}{\isacharparenleft}}p{\isaliteral{2C}{\isacharcomma}}{\isaliteral{5F}{\isacharunderscore}}{\isaliteral{2C}{\isacharcomma}}f{\isaliteral{2C}{\isacharcomma}}nxt{\isaliteral{2C}{\isacharcomma}}{\isaliteral{5F}{\isacharunderscore}}{\isaliteral{2C}{\isacharcomma}}pt{\isaliteral{29}{\isacharparenright}}\ {\isaliteral{3D}{\isacharequal}}\ me\ nxt\ p\ {\isaliteral{5B}{\isacharbrackleft}}{\isaliteral{5D}{\isacharbrackright}}\ pt{\isaliteral{3B}{\isacharsemicolon}}\isanewline

\ \ val\ {\isaliteral{28}{\isacharparenleft}}p{\isaliteral{2C}{\isacharcomma}}{\isaliteral{5F}{\isacharunderscore}}{\isaliteral{2C}{\isacharcomma}}f{\isaliteral{2C}{\isacharcomma}}nxt{\isaliteral{2C}{\isacharcomma}}{\isaliteral{5F}{\isacharunderscore}}{\isaliteral{2C}{\isacharcomma}}pt{\isaliteral{29}{\isacharparenright}}\ {\isaliteral{3D}{\isacharequal}}\ me\ nxt\ p\ {\isaliteral{5B}{\isacharbrackleft}}{\isaliteral{5D}{\isacharbrackright}}\ pt{\isaliteral{3B}{\isacharsemicolon}}\isanewline

\ \ val\ {\isaliteral{28}{\isacharparenleft}}p{\isaliteral{2C}{\isacharcomma}}{\isaliteral{5F}{\isacharunderscore}}{\isaliteral{2C}{\isacharcomma}}f{\isaliteral{2C}{\isacharcomma}}nxt{\isaliteral{2C}{\isacharcomma}}{\isaliteral{5F}{\isacharunderscore}}{\isaliteral{2C}{\isacharcomma}}pt{\isaliteral{29}{\isacharparenright}}\ {\isaliteral{3D}{\isacharequal}}\ me\ nxt\ p\ {\isaliteral{5B}{\isacharbrackleft}}{\isaliteral{5D}{\isacharbrackright}}\ pt{\isaliteral{3B}{\isacharsemicolon}}\isanewline

\ \ val\ {\isaliteral{28}{\isacharparenleft}}p{\isaliteral{2C}{\isacharcomma}}{\isaliteral{5F}{\isacharunderscore}}{\isaliteral{2C}{\isacharcomma}}f{\isaliteral{2C}{\isacharcomma}}nxt{\isaliteral{2C}{\isacharcomma}}{\isaliteral{5F}{\isacharunderscore}}{\isaliteral{2C}{\isacharcomma}}pt{\isaliteral{29}{\isacharparenright}}\ {\isaliteral{3D}{\isacharequal}}\ me\ nxt\ p\ {\isaliteral{5B}{\isacharbrackleft}}{\isaliteral{5D}{\isacharbrackright}}\ pt{\isaliteral{3B}{\isacharsemicolon}}\isanewline

\ \ val\ {\isaliteral{28}{\isacharparenleft}}p{\isaliteral{2C}{\isacharcomma}}{\isaliteral{5F}{\isacharunderscore}}{\isaliteral{2C}{\isacharcomma}}f{\isaliteral{2C}{\isacharcomma}}nxt{\isaliteral{2C}{\isacharcomma}}{\isaliteral{5F}{\isacharunderscore}}{\isaliteral{2C}{\isacharcomma}}pt{\isaliteral{29}{\isacharparenright}}\ {\isaliteral{3D}{\isacharequal}}\ me\ nxt\ p\ {\isaliteral{5B}{\isacharbrackleft}}{\isaliteral{5D}{\isacharbrackright}}\ pt{\isaliteral{3B}{\isacharsemicolon}}\isanewline

\ \ val\ {\isaliteral{28}{\isacharparenleft}}p{\isaliteral{2C}{\isacharcomma}}{\isaliteral{5F}{\isacharunderscore}}{\isaliteral{2C}{\isacharcomma}}f{\isaliteral{2C}{\isacharcomma}}nxt{\isaliteral{2C}{\isacharcomma}}{\isaliteral{5F}{\isacharunderscore}}{\isaliteral{2C}{\isacharcomma}}pt{\isaliteral{29}{\isacharparenright}}\ {\isaliteral{3D}{\isacharequal}}\ me\ nxt\ p\ {\isaliteral{5B}{\isacharbrackleft}}{\isaliteral{5D}{\isacharbrackright}}\ pt{\isaliteral{3B}{\isacharsemicolon}}\isanewline

\ \ val\ {\isaliteral{28}{\isacharparenleft}}p{\isaliteral{2C}{\isacharcomma}}{\isaliteral{5F}{\isacharunderscore}}{\isaliteral{2C}{\isacharcomma}}f{\isaliteral{2C}{\isacharcomma}}nxt{\isaliteral{2C}{\isacharcomma}}{\isaliteral{5F}{\isacharunderscore}}{\isaliteral{2C}{\isacharcomma}}pt{\isaliteral{29}{\isacharparenright}}\ {\isaliteral{3D}{\isacharequal}}\ me\ nxt\ p\ {\isaliteral{5B}{\isacharbrackleft}}{\isaliteral{5D}{\isacharbrackright}}\ pt{\isaliteral{3B}{\isacharsemicolon}}\ \ \ \ \ \ \ \ \ \isanewline

\ \ val\ {\isaliteral{28}{\isacharparenleft}}p{\isaliteral{2C}{\isacharcomma}}{\isaliteral{5F}{\isacharunderscore}}{\isaliteral{2C}{\isacharcomma}}f{\isaliteral{2C}{\isacharcomma}}nxt{\isaliteral{2C}{\isacharcomma}}{\isaliteral{5F}{\isacharunderscore}}{\isaliteral{2C}{\isacharcomma}}pt{\isaliteral{29}{\isacharparenright}}\ {\isaliteral{3D}{\isacharequal}}\ me\ nxt\ p\ {\isaliteral{5B}{\isacharbrackleft}}{\isaliteral{5D}{\isacharbrackright}}\ pt{\isaliteral{3B}{\isacharsemicolon}}\isanewline

\ \ {\isaliteral{28}{\isacharparenleft}}{\isaliteral{2A}{\isacharasterisk}}\isanewline

\ \ \ {\isaliteral{2A}{\isacharasterisk}}\ nxt\ {\isaliteral{3D}{\isacharequal}}{\isaliteral{2E}{\isachardot}}{\isaliteral{2E}{\isachardot}}{\isaliteral{2C}{\isacharcomma}}Check{\isaliteral{5F}{\isacharunderscore}}elementwise\ {\isaliteral{22}{\isachardoublequote}}Assumptions{\isaliteral{22}{\isachardoublequote}}{\isaliteral{29}{\isacharparenright}}\ \isanewline

\ \ \ {\isaliteral{2A}{\isacharasterisk}}{\isaliteral{29}{\isacharparenright}}\isanewline

\ \ val\ {\isaliteral{28}{\isacharparenleft}}p{\isaliteral{2C}{\isacharcomma}}{\isaliteral{5F}{\isacharunderscore}}{\isaliteral{2C}{\isacharcomma}}f{\isaliteral{2C}{\isacharcomma}}nxt{\isaliteral{2C}{\isacharcomma}}{\isaliteral{5F}{\isacharunderscore}}{\isaliteral{2C}{\isacharcomma}}pt{\isaliteral{29}{\isacharparenright}}\ {\isaliteral{3D}{\isacharequal}}\ me\ nxt\ p\ {\isaliteral{5B}{\isacharbrackleft}}{\isaliteral{5D}{\isacharbrackright}}\ pt{\isaliteral{3B}{\isacharsemicolon}}\ \ \ \ \ \ \ \ \ \isanewline

\ \ val\ {\isaliteral{28}{\isacharparenleft}}p{\isaliteral{2C}{\isacharcomma}}{\isaliteral{5F}{\isacharunderscore}}{\isaliteral{2C}{\isacharcomma}}f{\isaliteral{2C}{\isacharcomma}}nxt{\isaliteral{2C}{\isacharcomma}}{\isaliteral{5F}{\isacharunderscore}}{\isaliteral{2C}{\isacharcomma}}pt{\isaliteral{29}{\isacharparenright}}\ {\isaliteral{3D}{\isacharequal}}\ me\ nxt\ p\ {\isaliteral{5B}{\isacharbrackleft}}{\isaliteral{5D}{\isacharbrackright}}\ pt{\isaliteral{3B}{\isacharsemicolon}}\ f{\isadigit{2}}str\ f{\isaliteral{3B}{\isacharsemicolon}}\isanewline

\ \ {\isaliteral{28}{\isacharparenleft}}{\isaliteral{2A}{\isacharasterisk}}\isanewline

\ \ \ {\isaliteral{2A}{\isacharasterisk}}\ {\isaliteral{5B}{\isacharbrackleft}}z\ {\isaliteral{3D}{\isacharequal}}\ {\isadigit{1}}\ {\isaliteral{2F}{\isacharslash}}\ {\isadigit{2}}{\isaliteral{2C}{\isacharcomma}}\ z\ {\isaliteral{3D}{\isacharequal}}\ {\isaliteral{2D}{\isacharminus}}{\isadigit{1}}\ {\isaliteral{2F}{\isacharslash}}\ {\isadigit{4}}{\isaliteral{5D}{\isacharbrackright}}\isanewline

\ \ \ {\isaliteral{2A}{\isacharasterisk}}{\isaliteral{29}{\isacharparenright}}\isanewline

\ \ show{\isaliteral{5F}{\isacharunderscore}}pt\ pt{\isaliteral{3B}{\isacharsemicolon}}\ \isanewline

\ \ val\ SOME\ f\ {\isaliteral{3D}{\isacharequal}}\ parseNEW\ ctxt\ {\isaliteral{22}{\isachardoublequote}}{\isaliteral{5B}{\isacharbrackleft}}z{\isaliteral{3D}{\isacharequal}}{\isadigit{1}}{\isaliteral{2F}{\isacharslash}}{\isadigit{2}}{\isaliteral{2C}{\isacharcomma}}\ z{\isaliteral{3D}{\isacharequal}}{\isaliteral{2D}{\isacharminus}}{\isadigit{1}}{\isaliteral{2F}{\isacharslash}}{\isadigit{4}}{\isaliteral{5D}{\isacharbrackright}}{\isaliteral{22}{\isachardoublequote}}{\isaliteral{3B}{\isacharsemicolon}}\isanewline

{\isaliteral{2A7D}{\isacharverbatimclose}}%

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\isamarkupsubsection{Partial Fraction Decomposition\label{sec:pbz}%

}

\isamarkuptrue%

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\begin{isamarkuptext}%

\noindent We go on with the decomposion of our expression. Follow up the

       Calculation in Section~\ref{sec:calc:ztrans} Step~3 and later on

       Subproblem~1.%

\end{isamarkuptext}%

\isamarkuptrue%

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\isamarkupsubsubsection{Solutions of the Equation%

}

\isamarkuptrue%

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\begin{isamarkuptext}%

\noindent We get the solutions of the before solved equation in a list.%

\end{isamarkuptext}%

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\isatagML

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\ {\isaliteral{7B2A}{\isacharverbatimopen}}\isanewline

\ \ val\ SOME\ solutions\ {\isaliteral{3D}{\isacharequal}}\ parseNEW\ ctxt\ {\isaliteral{22}{\isachardoublequote}}{\isaliteral{5B}{\isacharbrackleft}}z{\isaliteral{3D}{\isacharequal}}{\isadigit{1}}{\isaliteral{2F}{\isacharslash}}{\isadigit{2}}{\isaliteral{2C}{\isacharcomma}}\ z{\isaliteral{3D}{\isacharequal}}{\isaliteral{2D}{\isacharminus}}{\isadigit{1}}{\isaliteral{2F}{\isacharslash}}{\isadigit{4}}{\isaliteral{5D}{\isacharbrackright}}{\isaliteral{22}{\isachardoublequote}}{\isaliteral{3B}{\isacharsemicolon}}\isanewline

\ \ term{\isadigit{2}}str\ solutions{\isaliteral{3B}{\isacharsemicolon}}\isanewline

\ \ atomty\ solutions{\isaliteral{3B}{\isacharsemicolon}}\isanewline

{\isaliteral{2A7D}{\isacharverbatimclose}}%

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\isamarkupsubsubsection{Get Solutions out of a List%

}

\isamarkuptrue%

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\begin{isamarkuptext}%

\noindent In {\sisac}'s CTP-based programming language: 

       \ttfamily let\$ \$s\_1 = NTH 1\$ solutions; \$s\_2 = NTH 2...\$ \normalfont

       can be usefull.%

\end{isamarkuptext}%

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\ {\isaliteral{7B2A}{\isacharverbatimopen}}\isanewline

\ \ val\ Const\ {\isaliteral{28}{\isacharparenleft}}{\isaliteral{22}{\isachardoublequote}}List{\isaliteral{2E}{\isachardot}}list{\isaliteral{2E}{\isachardot}}Cons{\isaliteral{22}{\isachardoublequote}}{\isaliteral{2C}{\isacharcomma}}\ {\isaliteral{5F}{\isacharunderscore}}{\isaliteral{29}{\isacharparenright}}\ {\isaliteral{24}{\isachardollar}}\ s{\isaliteral{5F}{\isacharunderscore}}{\isadigit{1}}\ {\isaliteral{24}{\isachardollar}}\ {\isaliteral{28}{\isacharparenleft}}Const\ {\isaliteral{28}{\isacharparenleft}}{\isaliteral{22}{\isachardoublequote}}List{\isaliteral{2E}{\isachardot}}list{\isaliteral{2E}{\isachardot}}Cons{\isaliteral{22}{\isachardoublequote}}{\isaliteral{2C}{\isacharcomma}}\ {\isaliteral{5F}{\isacharunderscore}}{\isaliteral{29}{\isacharparenright}}\isanewline

\ \ \ \ \ \ \ \ {\isaliteral{24}{\isachardollar}}\ s{\isaliteral{5F}{\isacharunderscore}}{\isadigit{2}}\ {\isaliteral{24}{\isachardollar}}\ Const\ {\isaliteral{28}{\isacharparenleft}}{\isaliteral{22}{\isachardoublequote}}List{\isaliteral{2E}{\isachardot}}list{\isaliteral{2E}{\isachardot}}Nil{\isaliteral{22}{\isachardoublequote}}{\isaliteral{2C}{\isacharcomma}}\ {\isaliteral{5F}{\isacharunderscore}}{\isaliteral{29}{\isacharparenright}}{\isaliteral{29}{\isacharparenright}}\ {\isaliteral{3D}{\isacharequal}}\ solutions{\isaliteral{3B}{\isacharsemicolon}}\isanewline

\ \ term{\isadigit{2}}str\ s{\isaliteral{5F}{\isacharunderscore}}{\isadigit{1}}{\isaliteral{3B}{\isacharsemicolon}}\isanewline

\ \ term{\isadigit{2}}str\ s{\isaliteral{5F}{\isacharunderscore}}{\isadigit{2}}{\isaliteral{3B}{\isacharsemicolon}}\isanewline

{\isaliteral{2A7D}{\isacharverbatimclose}}%

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\begin{isamarkuptext}%

\noindent The ansatz for the \em Partial Fraction Decomposion \normalfont

      requires to get the denominators of the partial fractions out of the 

      Solutions as:

      \begin{itemize}

      \item $\text{Denominator}_{1} = z - \text{Zeropoint}_{1}$

      \item $\text{Denominator}_{2} = z - \text{Zeropoint}_{2}$

      \item \ldots

      \end{itemize}%

\end{isamarkuptext}%

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\ {\isaliteral{7B2A}{\isacharverbatimopen}}\isanewline

\ \ val\ xx\ {\isaliteral{3D}{\isacharequal}}\ HOLogic{\isaliteral{2E}{\isachardot}}dest{\isaliteral{5F}{\isacharunderscore}}eq\ s{\isaliteral{5F}{\isacharunderscore}}{\isadigit{1}}{\isaliteral{3B}{\isacharsemicolon}}\isanewline

\ \ val\ s{\isaliteral{5F}{\isacharunderscore}}{\isadigit{1}}{\isaliteral{27}{\isacharprime}}\ {\isaliteral{3D}{\isacharequal}}\ HOLogic{\isaliteral{2E}{\isachardot}}mk{\isaliteral{5F}{\isacharunderscore}}binop\ {\isaliteral{22}{\isachardoublequote}}Groups{\isaliteral{2E}{\isachardot}}minus{\isaliteral{5F}{\isacharunderscore}}class{\isaliteral{2E}{\isachardot}}minus{\isaliteral{22}{\isachardoublequote}}\ xx{\isaliteral{3B}{\isacharsemicolon}}\isanewline

\ \ val\ xx\ {\isaliteral{3D}{\isacharequal}}\ HOLogic{\isaliteral{2E}{\isachardot}}dest{\isaliteral{5F}{\isacharunderscore}}eq\ s{\isaliteral{5F}{\isacharunderscore}}{\isadigit{2}}{\isaliteral{3B}{\isacharsemicolon}}\isanewline

\ \ val\ s{\isaliteral{5F}{\isacharunderscore}}{\isadigit{2}}{\isaliteral{27}{\isacharprime}}\ {\isaliteral{3D}{\isacharequal}}\ HOLogic{\isaliteral{2E}{\isachardot}}mk{\isaliteral{5F}{\isacharunderscore}}binop\ {\isaliteral{22}{\isachardoublequote}}Groups{\isaliteral{2E}{\isachardot}}minus{\isaliteral{5F}{\isacharunderscore}}class{\isaliteral{2E}{\isachardot}}minus{\isaliteral{22}{\isachardoublequote}}\ xx{\isaliteral{3B}{\isacharsemicolon}}\isanewline

\ \ term{\isadigit{2}}str\ s{\isaliteral{5F}{\isacharunderscore}}{\isadigit{1}}{\isaliteral{27}{\isacharprime}}{\isaliteral{3B}{\isacharsemicolon}}\isanewline

\ \ term{\isadigit{2}}str\ s{\isaliteral{5F}{\isacharunderscore}}{\isadigit{2}}{\isaliteral{27}{\isacharprime}}{\isaliteral{3B}{\isacharsemicolon}}\isanewline

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\begin{isamarkuptext}%

\noindent For the programming language a function collecting all the 

        above manipulations is helpful.%

\end{isamarkuptext}%

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\ {\isaliteral{7B2A}{\isacharverbatimopen}}\isanewline

\ \ fun\ fac{\isaliteral{5F}{\isacharunderscore}}from{\isaliteral{5F}{\isacharunderscore}}sol\ s\ {\isaliteral{3D}{\isacharequal}}\isanewline

\ \ \ \ let\ val\ {\isaliteral{28}{\isacharparenleft}}lhs{\isaliteral{2C}{\isacharcomma}}\ rhs{\isaliteral{29}{\isacharparenright}}\ {\isaliteral{3D}{\isacharequal}}\ HOLogic{\isaliteral{2E}{\isachardot}}dest{\isaliteral{5F}{\isacharunderscore}}eq\ s\isanewline

\ \ \ \ in\ HOLogic{\isaliteral{2E}{\isachardot}}mk{\isaliteral{5F}{\isacharunderscore}}binop\ {\isaliteral{22}{\isachardoublequote}}Groups{\isaliteral{2E}{\isachardot}}minus{\isaliteral{5F}{\isacharunderscore}}class{\isaliteral{2E}{\isachardot}}minus{\isaliteral{22}{\isachardoublequote}}\ {\isaliteral{28}{\isacharparenleft}}lhs{\isaliteral{2C}{\isacharcomma}}\ rhs{\isaliteral{29}{\isacharparenright}}\ end{\isaliteral{3B}{\isacharsemicolon}}\isanewline

{\isaliteral{2A7D}{\isacharverbatimclose}}\isanewline

\isanewline

\isacommand{ML}\isamarkupfalse%

\ {\isaliteral{7B2A}{\isacharverbatimopen}}\isanewline

\ \ fun\ mk{\isaliteral{5F}{\isacharunderscore}}prod\ prod\ {\isaliteral{5B}{\isacharbrackleft}}{\isaliteral{5D}{\isacharbrackright}}\ {\isaliteral{3D}{\isacharequal}}\isanewline

\ \ \ \ \ \ \ \ if\ prod\ {\isaliteral{3D}{\isacharequal}}\ e{\isaliteral{5F}{\isacharunderscore}}term\isanewline

\ \ \ \ \ \ \ \ then\ error\ {\isaliteral{22}{\isachardoublequote}}mk{\isaliteral{5F}{\isacharunderscore}}prod\ called\ with\ {\isaliteral{5B}{\isacharbrackleft}}{\isaliteral{5D}{\isacharbrackright}}{\isaliteral{22}{\isachardoublequote}}\ \isanewline

\ \ \ \ \ \ \ \ else\ prod\isanewline

\ \ \ \ {\isaliteral{7C}{\isacharbar}}\ mk{\isaliteral{5F}{\isacharunderscore}}prod\ prod\ {\isaliteral{28}{\isacharparenleft}}t\ {\isaliteral{3A}{\isacharcolon}}{\isaliteral{3A}{\isacharcolon}}\ {\isaliteral{5B}{\isacharbrackleft}}{\isaliteral{5D}{\isacharbrackright}}{\isaliteral{29}{\isacharparenright}}\ {\isaliteral{3D}{\isacharequal}}\isanewline

\ \ \ \ \ \ \ \ if\ prod\ {\isaliteral{3D}{\isacharequal}}\ e{\isaliteral{5F}{\isacharunderscore}}term\isanewline

\ \ \ \ \ \ \ \ then\ t\isanewline

\ \ \ \ \ \ \ \ else\ HOLogic{\isaliteral{2E}{\isachardot}}mk{\isaliteral{5F}{\isacharunderscore}}binop\ {\isaliteral{22}{\isachardoublequote}}Groups{\isaliteral{2E}{\isachardot}}times{\isaliteral{5F}{\isacharunderscore}}class{\isaliteral{2E}{\isachardot}}times{\isaliteral{22}{\isachardoublequote}}\ {\isaliteral{28}{\isacharparenleft}}prod{\isaliteral{2C}{\isacharcomma}}\ t{\isaliteral{29}{\isacharparenright}}\isanewline

\ \ \ \ {\isaliteral{7C}{\isacharbar}}\ mk{\isaliteral{5F}{\isacharunderscore}}prod\ prod\ {\isaliteral{28}{\isacharparenleft}}t{\isadigit{1}}\ {\isaliteral{3A}{\isacharcolon}}{\isaliteral{3A}{\isacharcolon}}\ t{\isadigit{2}}\ {\isaliteral{3A}{\isacharcolon}}{\isaliteral{3A}{\isacharcolon}}\ ts{\isaliteral{29}{\isacharparenright}}\ {\isaliteral{3D}{\isacharequal}}\isanewline

\ \ \ \ \ \ \ \ \ \ if\ prod\ {\isaliteral{3D}{\isacharequal}}\ e{\isaliteral{5F}{\isacharunderscore}}term\ \isanewline

\ \ \ \ \ \ \ \ \ \ then\ \isanewline

\ \ \ \ \ \ \ \ \ \ \ \ \ let\ val\ p\ {\isaliteral{3D}{\isacharequal}}\ \isanewline

\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ HOLogic{\isaliteral{2E}{\isachardot}}mk{\isaliteral{5F}{\isacharunderscore}}binop\ {\isaliteral{22}{\isachardoublequote}}Groups{\isaliteral{2E}{\isachardot}}times{\isaliteral{5F}{\isacharunderscore}}class{\isaliteral{2E}{\isachardot}}times{\isaliteral{22}{\isachardoublequote}}\ {\isaliteral{28}{\isacharparenleft}}t{\isadigit{1}}{\isaliteral{2C}{\isacharcomma}}\ t{\isadigit{2}}{\isaliteral{29}{\isacharparenright}}\isanewline

\ \ \ \ \ \ \ \ \ \ \ \ \ in\ mk{\isaliteral{5F}{\isacharunderscore}}prod\ p\ ts\ end\ \isanewline

\ \ \ \ \ \ \ \ \ \ else\ \isanewline

\ \ \ \ \ \ \ \ \ \ \ \ \ let\ val\ p\ {\isaliteral{3D}{\isacharequal}}\isanewline

\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ HOLogic{\isaliteral{2E}{\isachardot}}mk{\isaliteral{5F}{\isacharunderscore}}binop\ {\isaliteral{22}{\isachardoublequote}}Groups{\isaliteral{2E}{\isachardot}}times{\isaliteral{5F}{\isacharunderscore}}class{\isaliteral{2E}{\isachardot}}times{\isaliteral{22}{\isachardoublequote}}\ {\isaliteral{28}{\isacharparenleft}}prod{\isaliteral{2C}{\isacharcomma}}\ t{\isadigit{1}}{\isaliteral{29}{\isacharparenright}}\isanewline

\ \ \ \ \ \ \ \ \ \ \ \ \ in\ mk{\isaliteral{5F}{\isacharunderscore}}prod\ p\ {\isaliteral{28}{\isacharparenleft}}t{\isadigit{2}}\ {\isaliteral{3A}{\isacharcolon}}{\isaliteral{3A}{\isacharcolon}}\ ts{\isaliteral{29}{\isacharparenright}}\ end\ \isanewline

{\isaliteral{2A7D}{\isacharverbatimclose}}\isanewline

\isanewline

\isacommand{ML}\isamarkupfalse%

\ {\isaliteral{7B2A}{\isacharverbatimopen}}\isanewline

\ \ fun\ factors{\isaliteral{5F}{\isacharunderscore}}from{\isaliteral{5F}{\isacharunderscore}}solution\ sol\ {\isaliteral{3D}{\isacharequal}}\ \isanewline

\ \ \ \ let\ val\ ts\ {\isaliteral{3D}{\isacharequal}}\ HOLogic{\isaliteral{2E}{\isachardot}}dest{\isaliteral{5F}{\isacharunderscore}}list\ sol\isanewline

\ \ \ \ in\ mk{\isaliteral{5F}{\isacharunderscore}}prod\ e{\isaliteral{5F}{\isacharunderscore}}term\ {\isaliteral{28}{\isacharparenleft}}map\ fac{\isaliteral{5F}{\isacharunderscore}}from{\isaliteral{5F}{\isacharunderscore}}sol\ ts{\isaliteral{29}{\isacharparenright}}\ end{\isaliteral{3B}{\isacharsemicolon}}\isanewline

{\isaliteral{2A7D}{\isacharverbatimclose}}%

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\begin{isamarkuptext}%

\noindent This function needs to be packed such that it can be evaluated

        by the Lucas-Interpreter. Therefor we moved the function to the

        corresponding \ttfamily Equation.thy \normalfont in our case

        \ttfamily PartialFractions.thy \normalfont. The neccessary steps

        are quit the same as we have done with \ttfamliy get\_denominator 

        \normalfont before.%

\end{isamarkuptext}%

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\ {\isaliteral{7B2A}{\isacharverbatimopen}}\isanewline

\ \ {\isaliteral{28}{\isacharparenleft}}{\isaliteral{2A}{\isacharasterisk}}{\isaliteral{28}{\isacharparenleft}}{\isaliteral{22}{\isachardoublequote}}factors{\isaliteral{5F}{\isacharunderscore}}from{\isaliteral{5F}{\isacharunderscore}}solution{\isaliteral{22}{\isachardoublequote}}{\isaliteral{2C}{\isacharcomma}}\isanewline

\ \ \ \ {\isaliteral{28}{\isacharparenleft}}{\isaliteral{22}{\isachardoublequote}}Partial{\isaliteral{5F}{\isacharunderscore}}Fractions{\isaliteral{2E}{\isachardot}}factors{\isaliteral{5F}{\isacharunderscore}}from{\isaliteral{5F}{\isacharunderscore}}solution{\isaliteral{22}{\isachardoublequote}}{\isaliteral{2C}{\isacharcomma}}\isanewline

\ \ \ \ \ \ eval{\isaliteral{5F}{\isacharunderscore}}factors{\isaliteral{5F}{\isacharunderscore}}from{\isaliteral{5F}{\isacharunderscore}}solution\ {\isaliteral{22}{\isachardoublequote}}{\isaliteral{22}{\isachardoublequote}}{\isaliteral{29}{\isacharparenright}}{\isaliteral{29}{\isacharparenright}}{\isaliteral{2A}{\isacharasterisk}}{\isaliteral{29}{\isacharparenright}}\isanewline

\ \ \ \ \ \ \isanewline

\ \ fun\ eval{\isaliteral{5F}{\isacharunderscore}}factors{\isaliteral{5F}{\isacharunderscore}}from{\isaliteral{5F}{\isacharunderscore}}solution\ {\isaliteral{28}{\isacharparenleft}}thmid{\isaliteral{3A}{\isacharcolon}}string{\isaliteral{29}{\isacharparenright}}\ {\isaliteral{5F}{\isacharunderscore}}\isanewline

\ \ \ \ \ \ \ {\isaliteral{28}{\isacharparenleft}}t\ as\ Const\ {\isaliteral{28}{\isacharparenleft}}{\isaliteral{22}{\isachardoublequote}}Partial{\isaliteral{5F}{\isacharunderscore}}Fractions{\isaliteral{2E}{\isachardot}}factors{\isaliteral{5F}{\isacharunderscore}}from{\isaliteral{5F}{\isacharunderscore}}solution{\isaliteral{22}{\isachardoublequote}}{\isaliteral{2C}{\isacharcomma}}\ {\isaliteral{5F}{\isacharunderscore}}{\isaliteral{29}{\isacharparenright}}\ {\isaliteral{24}{\isachardollar}}\ sol{\isaliteral{29}{\isacharparenright}}\isanewline

\ \ \ \ \ \ \ \ \ thy\ {\isaliteral{3D}{\isacharequal}}\ {\isaliteral{28}{\isacharparenleft}}{\isaliteral{28}{\isacharparenleft}}let\ val\ prod\ {\isaliteral{3D}{\isacharequal}}\ factors{\isaliteral{5F}{\isacharunderscore}}from{\isaliteral{5F}{\isacharunderscore}}solution\ sol\isanewline

\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ in\ SOME\ {\isaliteral{28}{\isacharparenleft}}mk{\isaliteral{5F}{\isacharunderscore}}thmid\ thmid\ {\isaliteral{22}{\isachardoublequote}}{\isaliteral{22}{\isachardoublequote}}\isanewline

\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ {\isaliteral{28}{\isacharparenleft}}Print{\isaliteral{5F}{\isacharunderscore}}Mode{\isaliteral{2E}{\isachardot}}setmp\ {\isaliteral{5B}{\isacharbrackleft}}{\isaliteral{5D}{\isacharbrackright}}\isanewline

\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ {\isaliteral{28}{\isacharparenleft}}Syntax{\isaliteral{2E}{\isachardot}}string{\isaliteral{5F}{\isacharunderscore}}of{\isaliteral{5F}{\isacharunderscore}}term\ {\isaliteral{28}{\isacharparenleft}}thy{\isadigit{2}}ctxt\ thy{\isaliteral{29}{\isacharparenright}}{\isaliteral{29}{\isacharparenright}}\ prod{\isaliteral{29}{\isacharparenright}}\ {\isaliteral{22}{\isachardoublequote}}{\isaliteral{22}{\isachardoublequote}}{\isaliteral{2C}{\isacharcomma}}\isanewline

\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ Trueprop\ {\isaliteral{24}{\isachardollar}}\ {\isaliteral{28}{\isacharparenleft}}mk{\isaliteral{5F}{\isacharunderscore}}equality\ {\isaliteral{28}{\isacharparenleft}}t{\isaliteral{2C}{\isacharcomma}}\ prod{\isaliteral{29}{\isacharparenright}}{\isaliteral{29}{\isacharparenright}}{\isaliteral{29}{\isacharparenright}}\isanewline

\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ end{\isaliteral{29}{\isacharparenright}}\isanewline

\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ handle\ {\isaliteral{5F}{\isacharunderscore}}\ {\isaliteral{3D}{\isacharequal}}{\isaliteral{3E}{\isachargreater}}\ NONE{\isaliteral{29}{\isacharparenright}}\isanewline

\ \ \ {\isaliteral{7C}{\isacharbar}}\ eval{\isaliteral{5F}{\isacharunderscore}}factors{\isaliteral{5F}{\isacharunderscore}}from{\isaliteral{5F}{\isacharunderscore}}solution\ {\isaliteral{5F}{\isacharunderscore}}\ {\isaliteral{5F}{\isacharunderscore}}\ {\isaliteral{5F}{\isacharunderscore}}\ {\isaliteral{5F}{\isacharunderscore}}\ {\isaliteral{3D}{\isacharequal}}\ NONE{\isaliteral{3B}{\isacharsemicolon}}\isanewline

{\isaliteral{2A7D}{\isacharverbatimclose}}%

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\begin{isamarkuptext}%

\noindent The tracing output of the calc tree after apllying this

       function was \ttfamily 24 / factors\_from\_solution 

       [z = 1/ 2, z = -1 / 4])] \normalfont and the next step \ttfamily

       val nxt = ("Empty\_Tac", ...): tac'\_)\normalfont. These observations

       indicate, that the Lucas-Interpreter (LIP) does not know how to

       evaluate\\ \ttfamily factors\_from\_solution, \normalfont so we knew

       that there is something wrong or missing.%

\end{isamarkuptext}%

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\begin{isamarkuptext}%

\noindent First we isolate the difficulty in the program as follows:\\

      \ttfamily \par \noindent

        "(L\_L::bool list) = (SubProblem (PolyEq',"\^\\

        "[abcFormula,degree\_2,polynomial,univariate,equation],[no\_met])"\^\\

        "[BOOL equ, REAL zzz]);"\^\\

        "(facs::real) = factors\_from\_solution L\_L;"\^\\

        "(foo::real) = Take facs"\^\\

      \normalfont \par \noindent And see the tracing output:\\

         \ttfamily \par \noindent \lbrack\\

        ((\lbrack\rbrack, Frm), Problem 

          (Isac, \lbrack inverse, Z\_Transform, SignalProcessing\rbrack)),\\

        ((\lbrack 1\rbrack, Frm), X z = 3 / (z - 1 / 4 + -1 / 8 * (1 / z))),\\

        ((\lbrack 1\rbrack, Res), 

          ?X' z = 3 / (z * (z - 1 / 4 + -1 / 8 * (1 / z)))),\\

        ((\lbrack 2\rbrack, Res),

          ?X' z = 24 / (-1 + -2 * z + 8 * z \^\^\^ ~2)),\\

        ((\lbrack 3\rbrack, Pbl), 

          solve (-1 + -2 * z + 8 * z \^\^\^ ~2 = 0, z)),\\

        ((\lbrack 3,1\rbrack, Frm), -1 + -2 * z + 8 * z \^\^\^ ~2 = 0),\\

        ((\lbrack 3,1\rbrack, Res), 

          z = (- -2 + sqrt (-2 \^\^\^ ~2 - 4 * 8 * -1)) / (2 * 8)|\\

          z = (- -2 - sqrt (-2 \^\^\^ ~2 - 4 * 8 * -1)) / (2 * 8)),\\

        ((\lbrack 3,2\rbrack, Res), z = 1 / 2 | z = -1 / 4),\\

        ((\lbrack 3,3\rbrack, Res), \lbrack z = 1 / 2, z = -1 / 4\rbrack),\\

        ((\lbrack 3,4\rbrack, Res), \lbrack z = 1 / 2, z = -1 / 4\rbrack),\\

        ((\lbrack 3\rbrack, Res), \lbrack z = 1 / 2, z = -1 / 4\rbrack),\\

        ((\lbrack 4\rbrack, Frm), 

          factors\_from\_solution \lbrackz = 1 / 2, z = -1 / 4])\\

        \rbrack\\

      \normalfont \noindent In particular that:\\

      \ttfamily \par \noindent ((\lbrack 3\rbrack, Pbl),

        solve (-1 + -2 * z + 8 * z \^\^\^ ~2 = 0, z)),\\

      \normalfont \par \noindent Shows the equation which has been created in

      the program by: \ttfamily \\

      \noindent "(denom::real) = get\_denominator funterm;"\^ 

        ~(*get\_denominator*)\\

      "(equ::bool) = (denom = (0::real));"\^\\

      \noindent get\_denominator \normalfont has been evaluated successfully,

      but not\\ \ttfamily factors\_from\_solution.\normalfont

      So we stepwise compare with an analogous case, \ttfamily get\_denominator

      \normalfont successfully done above: We know that LIP evaluates

      expressions in the program by use of the \emph{srls}, so we try to get

      the original \emph{srls}.\\