ref: 4142b62431afba148dba3473c32f7063dce861e4 dir: /lib9/isnan-posix.c/
#include <lib9.h> int isNaN(double d) { return isnan(d); } int isInf(double d, int sign) { if(sign < 0) return isinf(d) < 0; return isinf(d); }