let E be set ; :: thesis: for A being Subset of (E ^omega)
for n being Nat st n > 0 holds
A |^ n c= A +
let A be Subset of (E ^omega); :: thesis: for n being Nat st n > 0 holds
A |^ n c= A +
let n be Nat; :: thesis: ( n > 0 implies A |^ n c= A + )
assume n > 0 ; :: thesis: A |^ n c= A +
then for x being set st x in A |^ n holds
x in A + by Th48;
hence A |^ n c= A + by TARSKI:def 3; :: thesis: verum