Логическое "и" на чистейшем Си

Это музыкой навеяло:

alexo@euromake:/tmp/and$ cat and.c
void *
true_(x, y)
void *x, *y;
{
        return x;
}

void *
false_(x, y)
void *x, *y;
{
        return y;
}

void *
bool_[] = {false_, true_};

void *
and(x, y)
void *(*x)(), *y;
{
        return x(y, x);
}

main(argc, argv)
char *argv[];
{
        int x = argv[1][0] - '0';
        int y = argv[2][0] - '0';

        return (true_ == and(bool_[x], bool_[y]));
}
alexo@euromake:/tmp/and$ cat Makefile
all: and
        ./and 0 0; echo $$?
        ./and 0 1; echo $$?
        ./and 1 0; echo $$?
        ./and 1 1; echo $$?

clean:
        -rm -f and
alexo@euromake:/tmp/and$ make
cc     and.c   -o and
./and 0 0; echo $?
0
./and 0 1; echo $?
0
./and 1 0; echo $?
0
./and 1 1; echo $?
1
alexo@euromake:/tmp/and$