let E be set ; :: thesis: for A being Subset of (E ^omega )
for m, n being Nat holds (A |^ m,n) ^^ (A * ) = (A * ) ^^ (A |^ m,n)

let A be Subset of (E ^omega ); :: thesis: for m, n being Nat holds (A |^ m,n) ^^ (A * ) = (A * ) ^^ (A |^ m,n)
let m, n be Nat; :: thesis: (A |^ m,n) ^^ (A * ) = (A * ) ^^ (A |^ m,n)
A1: (A * ) ^^ (A |^ m,n) c= (A |^ m,n) ^^ (A * )
proof
let x be set ; :: according to TARSKI:def 3 :: thesis: ( not x in (A * ) ^^ (A |^ m,n) or x in (A |^ m,n) ^^ (A * ) )
assume x in (A * ) ^^ (A |^ m,n) ; :: thesis: x in (A |^ m,n) ^^ (A * )
then consider a, b being Element of E ^omega such that
A2: a in A * and
A3: b in A |^ m,n and
A4: x = a ^ b by FLANG_1:def 1;
consider k being Nat such that
A5: a in A |^ k by A2, FLANG_1:42;
consider mn being Nat such that
A6: ( m <= mn & mn <= n ) and
A7: b in A |^ mn by A3, Th19;
( A |^ k c= A * & A |^ mn c= A |^ m,n ) by A6, Th20, FLANG_1:43;
then A8: (A |^ mn) ^^ (A |^ k) c= (A |^ m,n) ^^ (A * ) by FLANG_1:18;
a ^ b in A |^ (mn + k) by A7, A5, FLANG_1:41;
then a ^ b in (A |^ mn) ^^ (A |^ k) by FLANG_1:34;
hence x in (A |^ m,n) ^^ (A * ) by A4, A8; :: thesis: verum
end;
(A |^ m,n) ^^ (A * ) c= (A * ) ^^ (A |^ m,n)
proof
let x be set ; :: according to TARSKI:def 3 :: thesis: ( not x in (A |^ m,n) ^^ (A * ) or x in (A * ) ^^ (A |^ m,n) )
assume x in (A |^ m,n) ^^ (A * ) ; :: thesis: x in (A * ) ^^ (A |^ m,n)
then consider a, b being Element of E ^omega such that
A9: a in A |^ m,n and
A10: b in A * and
A11: x = a ^ b by FLANG_1:def 1;
consider k being Nat such that
A12: b in A |^ k by A10, FLANG_1:42;
consider mn being Nat such that
A13: ( m <= mn & mn <= n ) and
A14: a in A |^ mn by A9, Th19;
( A |^ k c= A * & A |^ mn c= A |^ m,n ) by A13, Th20, FLANG_1:43;
then A15: (A |^ k) ^^ (A |^ mn) c= (A * ) ^^ (A |^ m,n) by FLANG_1:18;
a ^ b in A |^ (k + mn) by A14, A12, FLANG_1:41;
then a ^ b in (A |^ k) ^^ (A |^ mn) by FLANG_1:34;
hence x in (A * ) ^^ (A |^ m,n) by A11, A15; :: thesis: verum
end;
hence (A |^ m,n) ^^ (A * ) = (A * ) ^^ (A |^ m,n) by A1, XBOOLE_0:def 10; :: thesis: verum