+/* Specification. */
+#ifdef USE_LONG_DOUBLE
+/* Specification found in math.h or isnanl-nolibm.h. */
+extern int rpl_isnanl (long double x);
+#elif ! defined USE_FLOAT
+/* Specification found in math.h or isnand-nolibm.h. */
+extern int rpl_isnand (double x);
+#else /* defined USE_FLOAT */
+/* Specification found in math.h or isnanf-nolibm.h. */
+extern int rpl_isnanf (float x);
+#endif
+