theorem NAT327:
  for a be non zero Integer, b be non trivial Nat holds
  b |-count a = 0 iff not b divides a
  proof
    let a be non zero Integer, b be non trivial Nat;
    reconsider c = |.a.| as non zero Nat;
    b > 1 by Def0; then
    not b divides |.a.| iff b |-count |.a.| = 0 by NAT_3:27;
    hence thesis by INT_2:16;
  end;
