ref: 1ec4d62ccec0872d1ecc64f6834e5ea8d36f7a1f dir: /tests/execute/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; }