let E be set ; :: thesis: for A being Subset of (E ^omega) holds (A ?) ^^ A = A ^^ (A ?)
let A be Subset of (E ^omega); :: thesis: (A ?) ^^ A = A ^^ (A ?)
A ? = A |^ (0,1) by Th79;
hence (A ?) ^^ A = A ^^ (A ?) by Th36; :: thesis: verum