UF theory bug fixes, code cleanup, and extra debugging output.

Enabled new UF theory by default.

Added some UF regressions.

Some work on the whole equality-over-bool-removed-in-favor-of-IFF
thing.  (Congruence closure module and other things have to handle
IFF as a special case of equality, etc..)

Added pre-rewriting to TheoryBool which rewrites:

  * (IFF true x)          =>  x
  * (IFF false x)         =>  (NOT x)
  * (IFF x true)          =>  x
  * (IFF x false)         =>  (NOT x)
  * (IFF x x)             =>  true
  * (IFF x (NOT x))       =>  false
  * (IFF (NOT x) x)       =>  false

  * (ITE true x y)        =>  x
  * (ITE false x y)       =>  y
  * (ITE cond x x)        =>  x

Added post-rewriting that does all of the above, plus normalize IFF and ITE:

  * (IFF x y)             =>  (IFF y x), if y < x
  * (ITE (NOT cond) x y)  =>  (ITE cond y x)

(Note: ITEs survive the removal-of-ITEs pass only if they are Boolean-valued.)

A little more debugging output from CNF stream, context pushes/pops,
ITE removal.

Some more documentation.

Fixed some typos.

1 files changed, 4 insertions, 0 deletions

diff --git a/src/theory/booleans/theory_bool.h b/src/theory/booleans/theory_bool.h
index 4d8620146..f492041b8 100644
--- a/src/theory/booleans/theory_bool.h
+++ b/src/theory/booleans/theory_bool.h
@@ -45,6 +45,10 @@ public:
   void check(Effort e) { Unimplemented(); }
   void propagate(Effort e) { Unimplemented(); }
   void explain(TNode n, Effort e) { Unimplemented(); }
+
+  RewriteResponse preRewrite(TNode n, bool topLevel);
+  RewriteResponse postRewrite(TNode n, bool topLevel);
+
   std::string identify() const { return std::string("TheoryBool"); }
 };