reserve A,B,C,D,E,F,G for Point of TOP-REAL 2;

theorem Th1:
  angle(A,B,A) = 0
  proof
    0 = angle(euc2cpx(A),euc2cpx(B),euc2cpx(A)) by COMPLEX2:79
     .= angle(A,B,A) by EUCLID_3:def 4;
    hence thesis;
  end;
