Plex is the scientific philosophy for "Understanding our understanting of the nature of Nature" of D.T.Ross (since late 1950s) which has a formalism of Formal Seeings and Formal Sayings (of and about PLMs -- Picture Language Models). This formalism is the same, but is precisely the opposite of, the accepted Formal Systems approach that is used in all rigorous mathematical, logical, and computer science work. In that approach, a Formal Language (with well-formation and derivation rules supporting proof) is coupled to a Model by a Satisfies predicate, in order to handle completeness and consistency matters. The difference is that, in Plex, the model comes first and the language (at each stage) is only what shows in the model, with "No-Rule" Seeing. Some PLMs are word-only -- with Mind's Eye Seeing for the picturing as well as the understanding. Some PLMs are oral/aural, also, so puns are more numerous. With No-Rule Seeing/Hearing (Viewing, is the general term), the Plex Paradigm applies (using the #2: Webster's International meaning: "a word in all its inflectional forms" in brief, where in Plex, "all" really means "all").
Plex has no axioms or assumptions, only definitions, and "Only that which is known by definition is known, by definition." is its Epistomology. The First Definition of Plex is "Nothing doesn't exist." -- which, since "Nothing" already is known to mean "that which does not exist," must and does define "existence" to be purely non-Nothingness, by definition including existences we cannot even imagine.
The Structured Analysis language, SA, derives from the Clear Model, which has no Picture at all -- only a brief Saying specifying what is Present and what is Absent:
.........everything relevant is present
AND nothing irrelevant is present
AND nothing relevant is absent
AND everything irrelevant is absent
(Small wonder that Plex annoys and is ignored by busy mathematicians.)
The actual Object Model -- satisfied by any physical object, but also adaptable to any rule-obeying object such as system software, and the like, will be added in full, soon, as well.