)
; when fold is finished, check sofar-pair
(\might_be_equal right_tail. and might_be_equal (isempty right_tail))
+
+; most elegant
+let list_equal = \lst. lst (\hd sofar. \lst. and (and (not (isempty lst)) (eq hd (head lst))) (sofar (tail lst))) isempty
+
-->