reserve E, x, y, X for set;
reserve A, B, C, D for Subset of E^omega;
reserve a, a1, a2, b, c, c1, c2, d, ab, bc for Element of E^omega;
reserve e for Element of E;
reserve i, j, k, l, n, n1, n2, m for Nat;

theorem Th6:
 for x being object holds <%x%> is Element of E^omega implies x in E
proof let x be object;
  assume <%x%> is Element of E^omega;
  then rng <%x%> c= E by RELAT_1:def 19;
  then {x} c= E by AFINSQ_1:33;
  hence thesis by ZFMISC_1:31;
end;
