The  Predication Substrate defines the compositional system of Element, Class of Element, and local predicates (Linkage) from which  SysFEAT's ontological structures are grown. It provides the internal structure of predication - classification, specialization, powertyping, and Compositionality - as a single, universe-stratified, mechanically verified engine that every higher layer inherits.

Unlike predicate logic (where a predicate is not a term) and graph theory (where an edge is not a node), a Linkage is simultaneously the mechanism of relating an Element that can be classified, specialized, and related to other entities. This self-applicability is what allows the framework to provide a theory of Relation - not just relations, but the ability to classify relations, specialize them, and compose them, using the same machinery that applies to the Entitys they relate.