`type 'a singleton_or_more````=`

`|` `Empty`
`|` `Singleton of 'a`
`|` `More`

``
`val singleton_or_more : fold:('t, 'a, 'a singleton_or_more) InferStdlib.IStd.Container.fold ‑> 't ‑> 'a singleton_or_more`
`val mem_nth : fold:('t, _, int) InferStdlib.IStd.Container.fold ‑> 't ‑> int ‑> bool`
`val forto : (int, int, 'accum) InferStdlib.IStd.Container.fold`
`val rev_map_to_list : fold:('t, 'a, 'b list) InferStdlib.IStd.Container.fold ‑> 't ‑> f:('a ‑> 'b) ‑> 'b list`
`val rev_filter_map_to_list : fold:('t, 'a, 'b list) InferStdlib.IStd.Container.fold ‑> 't ‑> f:('a ‑> 'b option) ‑> 'b list`