Z3 sources

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>

lib/spc_factoring.h

@@ -0,0 +1,66 @@
+/*++
+Copyright (c) 2006 Microsoft Corporation
+
+Module Name:
+
+    spc_factoring.h
+
+Abstract:
+
+    <abstract>
+
+Author:
+
+    Leonardo de Moura (leonardo) 2008-02-14.
+
+Revision History:
+
+--*/
+#ifndef _SPC_FACTORING_H_
+#define _SPC_FACTORING_H_
+
+#include"spc_unary_inference.h"
+#include"spc_statistics.h"
+
+namespace spc {
+
+    /**
+       \brief Functor for applying factoring.
+
+       - Equality Factoring
+       s = t or u = v or R
+       ==>
+       sigma(t != v or u = v or R)
+       
+       sigma = mgu(s, u)
+       sigma(s) not greater than sigma(t)
+       sigma(s = t) is eligible for paramodulation.
+       
+       - Factoring
+       P(t) or P(s) or R
+       ==>
+       sigma(P(t) or R)
+
+       sigma = mgu(t,s)
+       sigma(P(t)) is eligible for resolution.
+    */
+    class factoring : public unary_inference {
+    protected:
+        statistics & m_stats;
+        family_id    m_spc_fid;
+        virtual justification * mk_justification(justification * parent, unsigned num_lits, literal * new_lits) {
+            return mk_factoring_justification(m_manager, m_spc_fid, parent, num_lits, new_lits);
+        }
+        clause * mk_eq_fact_result(clause * cls, unsigned j, expr * lhs, expr * rhs);
+        void try_eq_factoring(clause * cls, unsigned j, expr * lhs, expr * rhs, ptr_vector<clause> & new_clauses);
+        void try_eq_factoring(clause * cls, unsigned i, ptr_vector<clause> & new_clauses);
+        void try_factoring(clause * cls, unsigned j, ptr_vector<clause> & new_clauses);
+    public:
+        factoring(ast_manager & m, order & ord, statistics & stats):unary_inference(m, ord), m_stats(stats), m_spc_fid(m.get_family_id("spc")) {}
+        virtual ~factoring() {}
+        void operator()(clause * cls, ptr_vector<clause> & new_clauses);
+    };
+};
+
+#endif /* _SPC_FACTORING_H_ */
+