`module type SeededHashedType = ``Hashtbl.SeededHashedType`

`type `

t

The type of the hashtable keys.

`val equal : ``t -> t -> bool`

The equality predicate used to compare keys.

`val hash : ``int -> t -> int`

A seeded hashing function on keys. The first argument is
the seed. It must be the case that if

`equal x y`

is true,
then `hash seed x = hash seed y`

for any value of `seed`

.
A suitable choice for `hash`

is the function `Hashtbl.seeded_hash`

below.