Alex's lecture gave us some examples to play with.

Size(GL(5, 3));

Filtered(Filtered([2..20000], n -> not IsPrime(n)), n -> ForAll(Filtered([2 .. n-1], b -> Gcd(b, n) = 1), b -> b^(n-1) mod n = 1));

Filtered(Filtered([2..2000], n -> not IsPrime(n)), n -> ForAll(Filtered([2 .. n-1], b -> Gcd(b, n) = 1), b -> b^(n-1) mod n = 1));