ref: 76f51c1570cb8e07e4dff1cc67b364519ead4d8a dir: /tests/0036-notneg.c/
int main() { int x; x = 4; if(!x != 0) return 1; if(!!x != 1) return 1; if(-x != 0 - 4) return 1; return 0; }