let E be set ; :: thesis: for A being Subset of (E ^omega )
for m, n, k, l being Nat holds (A |^ m,n) |^ k,l c= A *
let A be Subset of (E ^omega ); :: thesis: for m, n, k, l being Nat holds (A |^ m,n) |^ k,l c= A *
let m, n, k, l be Nat; :: thesis: (A |^ m,n) |^ k,l c= A *
let x be set ; :: according to TARSKI:def 3 :: thesis: ( not x in (A |^ m,n) |^ k,l or x in A * )
assume x in (A |^ m,n) |^ k,l ; :: thesis: x in A *
then consider kl being Nat such that
A1: ( k <= kl & kl <= l & x in (A |^ m,n) |^ kl ) by Th19;
(A |^ m,n) |^ kl c= A * by Th32, FLANG_1:60;
hence x in A * by A1; :: thesis: verum