reserve z,z1,z2 for Complex;
reserve r,x1,x2 for Real;
reserve p0,p,p1,p2,p3,q for Point of TOP-REAL 2;

theorem Th1:
  euc2cpx(cpx2euc(z))=z
proof
  (|[Re z,Im z]|)`1=Re z & (|[Re z,Im z]|)`2=Im z by EUCLID:52;
  hence thesis by COMPLEX1:13;
end;
