why are the definition of true and false in stdbool.h the exact opposite from the UNIX programs true and false?

stdbool.h is usually defined as: #define false 0 #define true 1 (Sources: OpenBSD , musl , etc.) whereas the unix program false - which just has a unsuccessful status code, is defined as: int main(int argc, char *argv[]) { return (1); } for completeness, the definition of the unix program true is: int main(int argc, char *argv[]) { return (0); } So clearly, it is the complete opposite of the value of false in stdbool.h. I have used the version from OpenBSD as the version from coreutils is more verbose What is the historical reason to make these different?