From e063e5258a2a223cc0ab3aee3cb30041c4b907f8 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Dejan=20Jovanovi=C4=87?= Date: Sat, 13 Feb 2010 00:55:40 +0000 Subject: [PATCH] Improvements to CNF conversion when already in CNF --- src/prop/cnf_stream.cpp | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) diff --git a/src/prop/cnf_stream.cpp b/src/prop/cnf_stream.cpp index 011d8ba5a..a96d499b6 100644 --- a/src/prop/cnf_stream.cpp +++ b/src/prop/cnf_stream.cpp @@ -318,6 +318,28 @@ SatLiteral TseitinCnfStream::toCNF(const Node& node) { void TseitinCnfStream::convertAndAssert(const Node& node) { Debug("cnf") << "convertAndAssert(" << node << ")" << endl; + // If the node is a conjuntion, we handle each conjunct separatelu + if (node.getKind() == AND) { + Node::iterator conjunct = node.begin(); + Node::iterator node_end = node.end(); + while (conjunct != node_end) { + convertAndAssert(*conjunct); + ++ conjunct; + } + return; + } + // If the node is a disjunction, we construct a clause and assert it + if (node.getKind() == OR) { + int nChildren = node.getNumChildren(); + SatClause clause(nChildren); + Node::iterator disjunct = node.begin(); + for (int i = 0; i < nChildren; ++ disjunct, ++ i) { + clause[i] = toCNF(*disjunct); + } + assertClause(clause); + return; + } + // Otherwise, we just convert using the definitional transformation assertClause(toCNF(node)); } -- 2.30.2