#version 100

/*
Adaptation of 7.pdl
*/

composite main() {}

composite example(in[] a, in[] b, out x) {
	new async(a);
	new async(b);
	new resolve(a, b, x);
}

primitive resolve(in[] a, in[] b, out x) {
	while (true) {
		synchronous {
			int i = 0;
			while (i < a.length && i < b.length) {
				if (fires(a[i]) && fires(b[i])) {
					put(x, create(0)); // send token to x
					break;
				}
				i++;
			}
			if (i >= a.length || i >= b.length)
				assert !fires(x);
		}
	}
}

primitive async(in[] a) {
	while (true) {
		synchronous {
			int i = 0;
			while (i < a.length)
				if (fires(a[i++])) break;
			while (i < a.length)
				assert !fires(a[i++]);
		}
	}
}