S_to_S_indexed.Monad_infix
val (>>|) : ('a, 'i, 'j) t -> ('a -> 'b) -> ('a, 'i, 'j) t
val (>>=) : ('a, 'i, 'j) t -> ('a -> ('a, 'i, 'j) t) -> ('a, 'i, 'j) t