add outline for ule constraints, change bit to var constraints

Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>

src/math/polysat/ule_constraint.cpp

@@ -0,0 +1,43 @@
+/*++
+Copyright (c) 2021 Microsoft Corporation
+
+Module Name:
+
+    polysat ule_constraints
+
+Author:
+
+    Nikolaj Bjorner (nbjorner) 2021-03-19
+    Jakob Rath 2021-04-6
+
+--*/
+
+#include "math/polysat/constraint.h"
+#include "math/polysat/solver.h"
+
+namespace polysat {
+
+    std::ostream& ule_constraint::display(std::ostream& out) const {
+        return out << m_lhs << " <=u " << m_rhs;
+    }
+
+    bool ule_constraint::propagate(solver& s, pvar v) {
+        return false;
+    }
+
+    constraint* ule_constraint::resolve(solver& s, pvar v) {
+        return nullptr;
+    }
+
+    void ule_constraint::narrow(solver& s) {
+    }
+
+    bool ule_constraint::is_always_false() {
+        return false;
+    }
+
+    bool ule_constraint::is_currently_false(solver& s) {
+        return false;
+    }
+
+}