Module Solver.T
module Fun : sig ... endA function symbol, like "f" or "plus" or "is_human" or "socrates"
module Ty : sig ... end with type t = Sidekick_base.Ty.t and type store = Sidekick_base.Ty.storeTypes
module Term : sig ... end with type t = Sidekick_base.Term.t and type store = Sidekick_base.Term.storeTerm structure.