ref: 75c92428225428c8fde2d015f010e608a0b12f1d dir: purgatorio/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); }