# define isinf(a) (fpclass(a) == FP_NINF || fpclass(a) == FP_PINF)
#endif
+/* solaris 10 it defines isnan such that only forte can compile it ... bad bad */
+#if (defined(HAVE_ISNAN) && defined(isnan) && defined(HAVE_FPCLASS))
+# undef isnan
+# define isnan(a) (fpclass(a) == FP_SNAN || fpclass(a) == FP_QNAN)
+#endif
+
/* for OSF1 Digital Unix */
#if (! defined(HAVE_ISINF) && defined(HAVE_FP_CLASS) && defined(HAVE_FP_CLASS_H))
# define HAVE_ISINF 1