let X be non empty set ; for R being RMembership_Func of X,X holds 0 iter R = Imf (X,X)
let R be RMembership_Func of X,X; 0 iter R = Imf (X,X)
ex F being sequence of (Funcs ([:X,X:],[.0,1.])) st
( 0 iter R = F . 0 & F . 0 = Imf (X,X) & ( for k being Nat ex Q being RMembership_Func of X,X st
( F . k = Q & F . (k + 1) = Q (#) R ) ) )
by Def9;
hence
0 iter R = Imf (X,X)
; verum