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 * )
thus (A *) ? = {(<%> E)} \/ (A *) by Th76
.= A * by FLANG_1:49, ZFMISC_1:46 ; :: thesis: (A ?) * = A *
thus (A ?) * = ({(<%> E)} \/ A) * by Th76
.= A * by FLANG_1:49, FLANG_1:69 ; :: thesis: verum