Welcome to GAP on CoCalc

Let's play with GAP

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

In [1]:

Size(GL(5, 3));

Out[1]:

475566474240

In [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));

Out[3]:

Error, user interrupt

In [0]:

Size(GL(5, 3));

In [0]:

In [0]:

In [2]:

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));

Out[2]:

[ 561, 1105, 1729 ]