| filter(s→l("jklmnopqrs"), s→l("tuvwxyz|~")) ≠ [] ⊦ |
⊦ filter ('j' ' + 'k' ' + 'l' ' + 'm' ' + 'n' ' + 'o' ' + 'p' ' + 'q' ' + 'r' ' + 's' ', 't' ' + 'u' ' + 'v' ' + 'w' ' + 'x' ' + 'y' ' + 'z' ' + '|' ' + '~' ') = []
Used simplifier rules: s2l-rec-01: str ≠ "" ⊦ s→l((* str)) = str.char1 ' + s→l(str.rstring);%s2l-empty: ⊦ s→l("") = [];% ⊦ (chars + chars0) + chars1 = chars + chars0 + chars1;% ⊦ chars + [] = chars;