ref: 7c7c7a23512be8c2f3100b61a5ea95f1d5e76d93 dir: /sys/src/ape/lib/ap/math/fmin.c/
#include <math.h> double fmin(double a, double b) { if(isNaN(a)) return b; if(isNaN(b)) return a; return a < b ? a : b; }