
theorem fresh3a:
for p being Prime holds card(Z/p) = p
proof
let p be Prime;
set F = Z/p; set M = MultGroup F;
   M = Z/Z*(p) by GR_CY_3:36; then
A: card M = p - 1 by INT_7:23;
   card M = card F - 1 by UNIROOTS:18;
hence thesis by A;
end;
