reserve a, b, c, d, e for Complex;

theorem :: REAL_2'31
  c <> 0 & a / c = b / c implies a = b
proof
  assume that
A1: c<>0 and
A2: a/c =b/c;
  a=b/c*c by A1,A2,Lm3;
  hence thesis by A1,Lm3;
end;
