Tried to reduce frame-axiom instantiations by saying the earlier heap must be a "heap anchor".

Currently, a heap is an anchor if it produced by a havoc (but not a direct update).

1 files changed, 8 insertions, 2 deletions

diff --git a/Test/VSI-Benchmarks/b3.dfy b/Test/VSI-Benchmarks/b3.dfy
index f59b0c3e..d47c4d4d 100644
--- a/Test/VSI-Benchmarks/b3.dfy
+++ b/Test/VSI-Benchmarks/b3.dfy
@@ -96,7 +96,7 @@ class Benchmark3 {
       if x < m { k := j; m := x; }

       j := j+1;

     }

-    

+

     j := 0;

     while j < k

       invariant j <= k;

@@ -108,10 +108,16 @@ class Benchmark3 {
       RotationLemma(old(q.contents), j, qc0, q.contents);

       j := j+1;

     }

-  

+

     assert j == k;  

     assert q.contents == old(q.contents)[k..] + old(q.contents)[..k];

+    ghost var qq := q.contents;

     m := q.Dequeue();

+    assert q.contents == qq[1..] && m == qq[0];

+    assert [m] + q.contents == qq;

+    assert |old(q.contents)| == |q.contents| + 1;

+

+    assert q.contents == old(q.contents)[k+1..] + old(q.contents)[..k];  

   }

 

   lemma RotationLemma(O: seq, j: nat, A: seq, C: seq)