Fixed some syntax errors and updated a test to asccount for numbers being more than 256.

test/arithmetic.cxx

@@ -65,12 +65,32 @@ BEGIN BOOST_PP_MOD(5, BOOST_PP_MOD(4, 3)) == 0 END
 
 BEGIN BOOST_PP_INC(0) == 1 END
 BEGIN BOOST_PP_INC(22) == 23 END
+
+#if BOOST_PP_LIMIT_MAG > 256
+
+BEGIN BOOST_PP_INC(256) == 257 END
+
+#else
+
 BEGIN BOOST_PP_INC(256) == 256 END
 
+#endif
+
 BEGIN BOOST_PP_INC(BOOST_PP_INC(0)) == 2 END
 BEGIN BOOST_PP_INC(BOOST_PP_INC(17)) == 19 END
+
+#if BOOST_PP_LIMIT_MAG > 256
+
+BEGIN BOOST_PP_INC(BOOST_PP_INC(255)) == 257 END
+
+#else
+
 BEGIN BOOST_PP_INC(BOOST_PP_INC(255)) == 256 END
 
+#endif
+
+
+
 /* decrement */
 
 BEGIN BOOST_PP_DEC(256) == 255 END