using a consistent naming convention for naming tactic subfolders

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

src/tactic/arith/purify_arith_tactic.h

@@ -0,0 +1,58 @@
+/*++
+Copyright (c) 2011 Microsoft Corporation
+
+Module Name:
+
+    purify_arith_tactic.h
+
+Abstract:
+
+    Tactic for eliminating arithmetic operators: DIV, IDIV, MOD,
+    TO_INT, and optionally (OP_IRRATIONAL_ALGEBRAIC_NUM).
+
+    This tactic uses the simplifier for also eliminating:
+    OP_SUB, OP_UMINUS, OP_POWER (optionally), OP_REM, OP_IS_INT. 
+    
+    Remarks:
+      - The semantics of division by zero is not specified. Thus,
+        uninterpreted functions are used.  An ExRCF procedure may
+        treat the unintepreted function applications as fresh
+        constants.  Then, in any model produced by this procedure,
+        the interpretation for division by zero must be checked.
+
+      - POWER operator can only be handled if the second argument is a
+        rational value.  The tactic has an option for preserving POWER
+        operator where the second argument is an integer.
+
+      - The semantics of (^ t (/ 1 k)) is not specified when t < 0 and
+        k is even. Similarly to the division by zero case,
+        uninterpreted function symbols are created.
+
+      - The semantics of (^ t 0) is not specified if t == 0. Thus,
+        uninterpreted function symbols are created.
+
+      - TO_REAL is not really outside of the RCF language
+        since it is only used for "casting".
+  
+      - All quantifiers must occur with positive polarity.
+        The tactic snf (with skolemization disabled) is applied 
+        to enforce that.
+   
+Author:
+
+    Leonardo de Moura (leonardo) 2011-12-30.
+
+Revision History:
+
+--*/
+#ifndef _PURIFY_ARITH_TACTIC_H_
+#define _PURIFY_ARITH_TACTIC_H_
+
+#include"params.h"
+class ast_manager;
+class tactic;
+
+tactic * mk_purify_arith_tactic(ast_manager & m, params_ref const & p = params_ref());
+
+#endif
+