Implementation

==============

- (#2 * x) = #2 * - x is not proved by arith

a simp command for terms

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primrec 

"(foorec [] []) = []"

"(foorec [] (y # ys)) = (y # (foorec [] ys))"

*** Primrec definition error:

*** extra variables on rhs: "y", "ys"

*** in

*** "((foorec [] ((y::'a_1) # (ys::'a_1 list))) = (y # (foorec [] ys)))"

*** At command "primrec".

Bessere Fehlermeldung!

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Relation: comp -> composition

Add map_cong?? (upto 10% slower)

Recdef: Get rid of function name in header.

Support mutual recursion (Konrad?)

use arith_tac in recdef to solve termination conditions?

-> new example in Recdef/termination

a tactic for replacing a specific occurrence:

apply(subst [2] thm)

it would be nice if @term could deal with ?-vars.

then a number of (unchecked!) @texts could be converted to @terms.

it would be nice if one could get id to the enclosing quotes in the [source] option.

More predefined functions for datatypes: map?

Induction rules for int: int_le/ge_induct?

Needed for ifak example. But is that example worth it?

Komischerweise geht das Splitten von _Annahmen_ auch mit simp_tac, was

ein generelles Feature ist, das man vielleicht mal abstellen sollte.

proper mutual simplification

defs with = and pattern matching??

Minor fixes in the tutorial

===========================

recdef: failed tcs no longer shown!

Advanced recdef: explain recdef_tc?

Adjust FP textbook refs: new Bird, Hudak

Discrete math textbook: Rosen?

adjust type of ^ in tab:overloading

an example of induction: !y. A --> B --> C ??

Explain type_definition and mention pre-proved thms in subset.thy?

-> Types/typedef

Appendix: Lexical: long ids.

Warning: infixes automatically become reserved words!

Forward ref from blast proof of Puzzle (AdvancedInd) to Isar proof?

recdef with nested recursion: either an example or at least a pointer to the

literature. In Recdef/termination.thy, at the end.

%FIXME, with one exception: nested recursion.

Syntax section: syntax annotations not just for consts but also for constdefs and datatype.

Appendix with list functions.

Minor additions to the tutorial, unclear where

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unfold?

Possible exercises

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Exercises

For extensionality (in Sets chapter): prove

valif o norm = valif

in If-expression case study (Ifexpr)

Nested inductive datatypes: another example/exercise:

 size(t) <= size(subst s t)?

insertion sort: primrec, later recdef

OTree:

 first version only for non-empty trees:

 Tip 'a | Node tree tree

 Then real version?

 First primrec, then recdef?

Ind. sets: define ABC inductively and prove

ABC = {rep A n @ rep B n @ rep C n. True}

Partial rekursive functions / Nontermination:

Exercise: ?! f. !i. f i = if i=0 then 1 else i*f(i-1)

(What about sum? Is there one, a unique one?)

Exercise

Better(?) sum i = fst(while (%(s,i). i=0) (%(s,i). (s+i,i-1)) (0,i))

Prove 0 <= i ==> sum i = i*(i+1) via while-rule

Possible examples/case studies

==============================

Trie: Define functional version

datatype ('a,'b)trie = Trie ('b option) ('a => ('a,'b)trie option)

lookup t [] = value t

lookup t (a#as) = case tries t a of None => None | Some s => lookup s as

Maybe as an exercise?

Trie: function for partial matches (prefixes). Needs sets for spec/proof.

Sets via ordered list of intervals. (Isa/Interval(2))

propositional logic (soundness and completeness?),

predicate logic (soundness?),

Tautology checker. Based on Ifexpr or prop.logic?

Include forward reference in relevant section.

Sorting with comp-parameter and with type class (<)

Recdef:more example proofs:

 if-normalization with measure function,

 nested if-normalization,

 quicksort

 Trie?

New book by Bird?

Steps Towards Mechanizing Program Transformations Using PVS by N. Shankar,

      Science of Computer Programming, 26(1-3):33-57, 1996. 

You can get it from http://www.csl.sri.com/scp95.html

J Moore article Towards a ...

Mergesort, JVM

Additional topics

=================

Recdef with nested recursion?

Extensionality: applications in

- boolean expressions: valif o bool2if = value

- Advanced datatypes exercise subst (f o g) = subst f o subst g

A look at the library?

Map.

Prototyping?

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