reserve X for set;
reserve a,b,c,k,m,n for Nat;
reserve i,j for Integer;
reserve r for Real;
reserve p,p1,p2 for Prime;

theorem Th65:
  n is_a_product_of_two_different_primes implies n >= 6
  proof
    given p,q being Prime such that
A1: p <> q and
A2: n = p*q;
A3: 6 = 2*3;
    2 <= p & 3 <= q or 3 <= p & 2 <= q by A1,Th40;
    hence thesis by A2,A3,XREAL_1:66;
  end;
