reserve V, C for set;
reserve A, B, D for Element of Fin PFuncs (V, C);
reserve s for Element of PFuncs (V,C);

theorem Th24:
  mi (A ^ A) = mi A
proof
  thus mi (A ^ A) = mi (A ^ A \/ A) by Th23,XBOOLE_1:12
    .= mi A by Lm4;
end;
