theorem Th10:
  for f being Function of TOP-REAL 2,R^1 st f=proj1 holds f is continuous
proof
  let f be Function of TOP-REAL 2,R^1;
  assume f=proj1;
  then 1 in Seg 2 & for p being Element of TOP-REAL 2 holds f.p=p/.1 by
FINSEQ_1:1,JORDAN2B:30;
  hence thesis by JORDAN2B:18;
end;
