--- /dev/null
+// ----------------------------------------------------------------------------
+// $Id$
+// ----------------------------------------------------------------------------
+// Public Domain C Library - http://pdclib.sourceforge.net
+// This code is Public Domain. Use, modify, and redistribute at will.
+// ----------------------------------------------------------------------------
+
+double nan( const char *str ) { /* TODO */ };
+float nanf( const char *str ) { /* TODO */ };
+long double nanl( const char *str ) { /* TODO */ };