
theorem Th8:
  for T1,T2 being TA-structure st the TA-structure of T1 = the
  TA-structure of T2 holds T1 is consistent implies T2 is consistent
proof
  let T1,T2 be TA-structure such that
A1: the TA-structure of T1 = the TA-structure of T2 and
A2: for t being type of T1 for a being adjective of T1 st a in adjs t
  holds not non-a in adjs t;
  let t2 be type of T2, a2 be adjective of T2;
  reconsider a1 = a2 as adjective of T1 by A1;
  reconsider t1 = t2 as type of T1 by A1;
  assume a2 in adjs t2;
  then not non-a1 in adjs t1 by A1,A2;
  hence thesis by A1;
end;
