We first introduce the intuitive idea of a relation of grounding between facts . Then we propose a definition of this idea, based on a certain theory of the structure of facts . Finally we consider the idea of proofs of a special kind, namely proofs which follow the grounds of what is proved.

We define a concept of truthmaker function, and prove the functional completeness, w.r.t. truthmaker functions in this sense, of a set of four-valued functions corresponding to standard connectives of the system of relevance logic known as First-Degree Entailment or Belnap–Dunn logic.

We sketch a general theory of complex objects and their constituents.