ANY
This is the second-most general type in Avail's type lattice. It is the only direct descendant of top (⊤), and all types except ⊤ are subtypes of it. Like ⊤, all Avail objects are instances of ANY. Technically there is also a nil, but that is only used internally by the Avail machinery (e.g., the value of an unassigned variable) and can never be manipulated by an Avail program.
Properties
An array of A_Types, where the entries correspond to ordinals of other Types, and hold the intersection of that type and the current type.
A boolean array where the entries correspond to ordinals of other Types. They are true precisely when the type with that ordinal is a supertype of the current type.
An array of A_Types, where the entries correspond to ordinals of other Types, and hold the unions of that type and the current type.