reserve x for set;
reserve a,b,d,ra,rb,r0,s1,s2 for Real;
reserve r,s,r1,r2,r3,rc for Real;
reserve p,q,q1,q2 for Point of TOP-REAL 2;
reserve X,Y,Z for non empty TopSpace;

theorem Th11:
  for f being Function of TOP-REAL 2,R^1 st f=proj2 holds f is continuous
proof
  let f be Function of TOP-REAL 2,R^1;
  assume f=proj2;
  then 2 in Seg 2 & for p being Element of TOP-REAL 2 holds f.p=p/.2 by
FINSEQ_1:1,JORDAN2B:30;
  hence thesis by JORDAN2B:18;
end;
