theorem Th29:
  (Mx2Tran M).0.TOP-REAL n = 0.TOP-REAL m
proof
  set TRn=the Element of TOP-REAL n;
  set MT=Mx2Tran M;
  0.TOP-REAL n =TRn-TRn by RLVECT_1:5;
  hence MT.0.TOP-REAL n=(MT.TRn)-(MT.TRn) by Th28
   .=0.TOP-REAL m by RLVECT_1:5;
end;
