theorem
  n in Seg m implies PROJ(m,n) is continuous
  proof
    assume
A1: n in Seg m;
A2: m in NAT by ORDINAL1:def 12;
    for p being Element of TOP-REAL m holds PROJ(m,n).p = p/.n by Def6;
    hence thesis by A2,A1,JORDAN2B:18;
  end;
