Add contexts capability interface

Author: peterschrammel

src/solvers/prop/prop_context.h

@@ -0,0 +1,28 @@
+/*******************************************************************\
+
+Module: Context-based Incremental Solver Interface
+
+Author: Peter Schrammel
+
+\*******************************************************************/
+
+/// \file
+/// Context-based interface for incremental solvers
+
+#ifndef CPROVER_SOLVERS_PROP_PROP_CONTEXT_H
+#define CPROVER_SOLVERS_PROP_PROP_CONTEXT_H
+
+class prop_contextt
+{
+public:
+  /// Push a new context on the stack
+  /// This context becomes a child context nested in the current context.
+  virtual void push_context() = 0;
+
+  /// Pop the current context
+  virtual void pop_context() = 0;
+
+  virtual ~prop_contextt() = default;
+};
+
+#endif // CPROVER_SOLVERS_PROP_PROP_CONTEXT_H