Spacer engine for HORN logic

The algorithms implemented in the engine are described in the following papers

Anvesh Komuravelli, Nikolaj Bjørner, Arie Gurfinkel, Kenneth L. McMillan:
Compositional Verification of Procedural Programs using Horn Clauses over Integers and Arrays. FMCAD 2015: 89-96

Nikolaj Bjørner, Arie Gurfinkel:
Property Directed Polyhedral Abstraction. VMCAI 2015: 263-281

Anvesh Komuravelli, Arie Gurfinkel, Sagar Chaki:
SMT-Based Model Checking for Recursive Programs. CAV 2014: 17-34

src/muz/spacer/spacer_qe_project.h

@@ -0,0 +1,49 @@
+/*++
+Copyright (c) 2017 Arie Gurfinkel
+
+Module Name:
+
+    spacer_qe_project.h
+
+Abstract:
+
+    Model-based projection
+
+Author:
+
+    Anvesh Komuravelli
+    Arie Gurfinkel (arie)
+
+Notes:
+
+--*/
+#ifndef SPACER_QE_PROJECT_H_
+#define SPACER_QE_PROJECT_H_
+
+#include "model.h"
+#include "expr_map.h"
+
+namespace qe {
+    /**
+       Loos-Weispfenning model-based projection for a basic conjunction.
+       Lits is a vector of literals.
+       return vector of variables that could not be projected.
+     */
+    expr_ref arith_project(model& model, app_ref_vector& vars, expr_ref_vector const& lits);
+
+    void arith_project(model& model, app_ref_vector& vars, expr_ref& fml);
+
+    void arith_project(model& model, app_ref_vector& vars, expr_ref& fml, expr_map& map);
+
+    void array_project_eqs (model& model, app_ref_vector& arr_vars, expr_ref& fml, app_ref_vector& aux_vars);
+
+    void reduce_array_selects (model& mdl, app_ref_vector const& arr_vars, expr_ref& fml, bool reduce_all_selects = false);
+
+    void reduce_array_selects (model& mdl, expr_ref& fml);
+
+    void array_project_selects (model& model, app_ref_vector& arr_vars, expr_ref& fml, app_ref_vector& aux_vars);
+
+    void array_project (model& model, app_ref_vector& arr_vars, expr_ref& fml, app_ref_vector& aux_vars, bool reduce_all_selects = false);
+};
+
+#endif