all_ones = !0;
u8 = unsigned(8);
s4 = signed(4);

fn inv(input: u8) -> (output1: u8, output2: u8) {
    .output1 = !input;
    .output2 = input ^ x;
    x = all_ones;
}

fn arith(a: u8, b: u8, c: s4) ->
        (x: u8, y: u8, z: bit) {
    c = .c + 2;
    .x = a + b - c as integer;
    .y = (x * b) as u8;
    .z = x <= y as integer;
}

fn mux(a: u8, opt: unsigned(3)) -> (y: u8) {
    .y = y;
    match opt {
        0 => { .y = a; }
        1, 2 => { .y = !a; }
        3 => { .y = 3; }
    } else {
        .y = a ^ 0b10100101;
    }
}

fn counter(
    clk: bit,
    aclear: bit,
    enable: bit,
) -> (
    val: unsigned(4),
) {
    .val = val;
    !aclear => val = 0 as unsigned(4);
    @clk => val = next;
    if enable {
        .next = val + 1;
    } else {
        .next = val;
    }
}