`include AbstractDomain.S`
`type astate`````
`val (<=) : lhs:astate ‑> rhs:astate ‑> bool`

the partial order induced by join

`val join : astate ‑> astate ‑> astate`
`val widen : prev:astate ‑> next:astate ‑> num_iters:int ‑> astate`
`val pp : InferModules.AbstractDomain.F.formatter ‑> astate ‑> unit`
`val empty : astate`

The bottom value of the domain. Naming it empty instead of bottom helps to bind the empty value for sets and maps to the natural definition for bottom

`val is_empty : astate ‑> bool`

Return true if this is the bottom value