let E be set ; :: thesis: for A being Subset of (E ^omega ) holds A |^ 0 = {(<%> E)}
let A be Subset of (E ^omega ); :: thesis: A |^ 0 = {(<%> E)}
consider concat being Function of NAT ,(bool (E ^omega )) such that
A1: ( A |^ 0 = concat . 0 & concat . 0 = {(<%> E)} & ( for i being Nat holds concat . (i + 1) = (concat . i) ^^ A ) ) by Def2;
thus A |^ 0 = {(<%> E)} by A1; :: thesis: verum