theorem
  for T1,T2 being quasi-type of C
  st adjs T1 = adjs T2 & the_base_of T1 = the_base_of T2
  holds T1 = T2
proof
  let T1,T2 be quasi-type of C;
  T1 = (adjs T1) ast the_base_of T1;
  hence thesis by Th80;
end;
