Adding test for issue #79.

examples/bts/79_compute_unsound.mlw

+module Soundness
+  use import int.Int
+  use HighOrd
+
+  function f0 (x y z:int) : int = x * y + z
+  predicate p (f:int -> int) =
+    f (-1) = 0 && forall n:int. f n = f 0 + (f 1 - f 0) * n
+
+  lemma A : forall y z:int. p (\x. f0 x y z) <-> y = z
+  meta rewrite prop A
+
+  (* compute_specified should not solve this goal.
+     0 = 0 was added so that compute_specified progress on this goal even when 
+     not unsound.
+  *)
+  lemma Fail : 0 = 0 /\ p (\x. f0 x x x)
+
+  lemma Absurd : false
+end

examples/bts/79_compute_unsound/why3session.xml

+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE why3session PUBLIC "-//Why3//proof session v5//EN"
+"http://why3.lri.fr/why3session.dtd">
+<why3session shape_version="4">
+<prover id="0" name="CVC4" version="1.5" timelimit="5" steplimit="0" memlimit="1000"/>
+<file name="../79_compute_unsound.mlw">
+<theory name="Soundness" sum="aa1c41b51a76f536179c52b8dcf8a473">
+ <goal name="A" proved="true">
+ <proof prover="0"><result status="valid" time="0.17"/></proof>
+ </goal>
+ <goal name="Fail">
+ <transf name="compute_specified" >
+  <goal name="Fail.0">
+  </goal>
+ </transf>
+ </goal>
+ <goal name="Absurd" proved="true">
+ <proof prover="0"><result status="valid" time="0.02"/></proof>
+ </goal>
+</theory>
+</file>
+</why3session>

tests/demo-itp.mlw

@@ -49,7 +49,7 @@ module Soundness
     f (-1) = 0 && forall n:int. f n = f 0 + (f 1 - f 0) * n
   lemma A : forall y z:int. p (\x. f0 x y z) <-> y = z
   meta rewrite prop A
-  lemma Fail : p (\x. f0 x x x)
+  lemma Fail : 0 = 0 /\ p (\x. f0 x x x)
   lemma Absurd : false
 end