 reserve x for Real,
    p,k,l,m,n,s,h,i,j,k1,t,t1 for Nat,
    X for Subset of REAL;
reserve x for object, X,Y,Z for set;

theorem Th29:
  card Segm n in card Segm m iff n < m
proof
  card Segm n c< card Segm m iff
     card Segm n c= card Segm m & card Segm n <> card Segm m;
  hence thesis by Th27,ORDINAL1:11,def 2;
end;
