intermed. Build_Inverse_Z_Transform:
got ambiguous parse trees from get_denominator in 2 theories ?!?
thus get_denominator shifted to Rational.thy
ATTENTION: "Rational.is'_ratpolyexp" has '
but get_denominator only works without '
1 (* Title: partial fraction decomposition
3 (c) due to copyright terms
6 "--------------------------------------------------------";
7 "table of contents --------------------------------------";
8 "--------------------------------------------------------";
9 "----------- get_denominator ----------------------------";
10 "--------------------------------------------------------";
11 "--------------------------------------------------------";
12 "--------------------------------------------------------";