reserve a,b,i,k,m,n for Nat;
reserve s,z for non zero Nat;
reserve c for Complex;

theorem Th63:
  1 <= a implies 2|^(2|^z) + (6*a-1) is non prime
  proof
    set p = 2|^(2|^z) + (6*a-1);
    assume
A1: 1 <= a;
    assume 2|^(2|^z) + (6*a-1) is prime;
    then 3 = p by Th62;
    hence thesis by A1,Th61;
  end;
