#version 100

composite main(out c) {
	channel ao -> ai;
    channel bo -> bi;
	new sync(ai, bo);
	new binary_replicator(bi, ao, c);
}

primitive sync(in a, out b) {
    while (true) {
        synchronous {
            if (fires(a) && fires(b)) {
            	msg x = get(a);
            	put(b, x);
            } else {
                assert !fires(a) && !fires(b);
            }
        }
    }
}

primitive binary_replicator(in b, out a, out c) {
    while (true) {
        synchronous {
            if (fires(b) && fires(a) && fires(c)) {
                msg x = get(b);
                put(a, x);
                put(c, x);
            } else {
                assert !fires(a) && !fires(b) && !fires(c);
            }
        }
    }
}