reserve i,j,k,n,m,l,s,t for Nat;
reserve a,b for Real;
reserve F for real-valued FinSequence;
reserve z for Complex;
reserve x,y for Complex;
reserve r,s,t for natural Number;

theorem
  m gcd 1 = 1
proof
  set M = m gcd 1;
A1: 1 divides M by NAT_D:6;
  M divides 1 by NAT_D:def 5;
  hence thesis by A1,NAT_D:5;
end;
