(* member(x,L) tests if x appears on list L *) fun member(x,nil) = false | member(x,y::ys) = if x=y then true else member(x,ys); (* memberAll(ch,L) checks that character ch and all following characters up to "z" are on list L *) fun memberAll(ch,L) = if ch > #"z" then true else member(ch,L) andalso memberAll(chr(ord(ch)+1),L); memberAll(#"a",explode("qwertyuiopasdfghjklzxcvbnm"));