pollution: num
extern intmax_t imaxabs(intmax_t num); 

pollution: numer
pollution: denom
extern imaxdiv_t imaxdiv(intmax_t numer, intmax_t denom); 

pollution: string
pollution: base
extern intmax_t strtoimax(const char *string, char **_end, int base); 

pollution: string
pollution: base
extern uintmax_t strtoumax(const char *string, char **_end, int base);