diff options
author | Morgan Deters <mdeters@gmail.com> | 2010-08-19 23:49:58 +0000 |
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committer | Morgan Deters <mdeters@gmail.com> | 2010-08-19 23:49:58 +0000 |
commit | ad24cbdb3462b2b2dd312aab2f1f33d9bbcac00e (patch) | |
tree | b783098b4d72422826890c46870436cbeae0788d /src/prop | |
parent | 29c72e0fd6d0161de275060bbd05370394f1f708 (diff) |
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.
Diffstat (limited to 'src/prop')
-rw-r--r-- | src/prop/cnf_stream.cpp | 14 |
1 files changed, 9 insertions, 5 deletions
diff --git a/src/prop/cnf_stream.cpp b/src/prop/cnf_stream.cpp index 5f8eb12b9..c719c66da 100644 --- a/src/prop/cnf_stream.cpp +++ b/src/prop/cnf_stream.cpp @@ -100,10 +100,10 @@ Node CnfStream::getNode(const SatLiteral& literal) { } SatLiteral CnfStream::convertAtom(TNode node) { - Assert(!isCached(node), "atom already mapped!"); - Debug("cnf") << "convertAtom(" << node << ")" << endl; + Assert(!isCached(node), "atom already mapped!"); + bool theoryLiteral = node.getKind() != kind::VARIABLE; SatLiteral lit = newLiteral(node, theoryLiteral); @@ -245,6 +245,8 @@ SatLiteral TseitinCnfStream::handleIff(TNode iffNode) { Assert(iffNode.getKind() == IFF, "Expecting an IFF expression!"); Assert(iffNode.getNumChildren() == 2, "Expecting exactly 2 children!"); + Debug("cnf") << "handleIff(" << iffNode << ")" << endl; + // Convert the children to CNF SatLiteral a = toCNF(iffNode[0]); SatLiteral b = toCNF(iffNode[1]); @@ -287,7 +289,7 @@ SatLiteral TseitinCnfStream::handleIte(TNode iteNode) { Assert(iteNode.getKind() == ITE); Assert(iteNode.getNumChildren() == 3); - Debug("cnf") << "handlIte(" << iteNode[0] << " " << iteNode[1] << " " << iteNode[2] << ")" << endl; + Debug("cnf") << "handleIte(" << iteNode[0] << " " << iteNode[1] << " " << iteNode[2] << ")" << endl; SatLiteral condLit = toCNF(iteNode[0]); SatLiteral thenLit = toCNF(iteNode[1]); @@ -353,8 +355,10 @@ SatLiteral TseitinCnfStream::toCNF(TNode node, bool negated) { nodeLit = handleAnd(node); break; case EQUAL: - if(node[0].getType().isBoolean() && node[1].getType().isBoolean()) { - nodeLit = handleIff(node[0].iffNode(node[1])); + if(node[0].getType().isBoolean()) { + // should have an IFF instead + Unreachable("= Bool Bool shouldn't be possible ?!"); + //nodeLit = handleIff(node[0].iffNode(node[1])); } else { nodeLit = convertAtom(node); } |