For another example: the type of denotations of the untyped lambda calculus is datatype D = D of (D → D) The problem of solving domain equations is concerned with finding domains that model these kinds of datatypes. One approach, roughly speaking, is to consider the collection of all domains as a domain itself, and then solve the recursive definition there.
For another example: the type of denotations of the untyped lambda calculus is datatype D = D of (D → D) The problem of solving domain equations is concerned with finding domains that model these kinds of datatypes. One approach, roughly speaking, is to consider the collection of all domains as a domain itself, and then solve the recursive definition there.