let E be set ; for A being Subset of (E ^omega)
for k, m, n being Nat holds (A |^ k) |^ (m,n) c= A *
let A be Subset of (E ^omega); for k, m, n being Nat holds (A |^ k) |^ (m,n) c= A *
let k, m, n be Nat; (A |^ k) |^ (m,n) c= A *
let x be object ; TARSKI:def 3 ( not x in (A |^ k) |^ (m,n) or x in A * )
assume
x in (A |^ k) |^ (m,n)
; x in A *
then consider mn being Nat such that
m <= mn
and
mn <= n
and
A1:
x in (A |^ k) |^ mn
by Th19;
A2:
A |^ (k * mn) c= A *
by FLANG_1:42;
x in A |^ (k * mn)
by A1, FLANG_1:34;
hence
x in A *
by A2; verum