add nla_lemma.h

Signed-off-by: Lev Nachmanson <levnach@hotmail.com>

src/math/lp/nla_lemma.h

@@ -0,0 +1,40 @@
+/*++
+  Copyright (c) 2017 Microsoft Corporation
+
+  Module Name:
+
+  nla_core.h
+
+  Author:
+  Nikolaj Bjorner (nbjorner)
+  Lev Nachmanson (levnach)
+
+--*/
+#pragma once
+namespace nla {
+struct ineq {
+    lp::lconstraint_kind m_cmp;
+    lp::lar_term         m_term;
+    rational             m_rs;
+    ineq(lp::lconstraint_kind cmp, const lp::lar_term& term, const rational& rs) : m_cmp(cmp), m_term(term), m_rs(rs) {}
+    bool operator==(const ineq& a) const {
+        return m_cmp == a.m_cmp && m_term == a.m_term && m_rs == a.m_rs;
+    }
+    const lp::lar_term& term() const { return m_term; };
+    lp::lconstraint_kind cmp() const { return m_cmp;  };
+    const rational& rs() const { return m_rs; };
+};
+
+class lemma {
+    vector<ineq>     m_ineqs;
+    lp::explanation  m_expl;
+public:
+    void push_back(const ineq& i) { m_ineqs.push_back(i);}
+    size_t size() const { return m_ineqs.size() + m_expl.size(); }
+    const vector<ineq>& ineqs() const { return m_ineqs; }
+    vector<ineq>& ineqs() { return m_ineqs; }
+    lp::explanation& expl() { return m_expl; }
+    const lp::explanation& expl() const { return m_expl; }
+    bool is_conflict() const { return m_ineqs.empty() && !m_expl.empty(); }
+};
+}