You may not believe me, but the If-and-only-If (IFF) operator means essence in object-oriented ontology. Some object-oriented ontologists may even have forgotten that.
But I'll tell you why it's true. For one thing, object-oriented ontology is not necessarily the terminology you need to describe it. In fact, I'm only throwing object-oriented ontologists into this because I think they're the most likely to have discovered this property already. Other highly likely contenders are Alfred North Whitehead and Bertrand Russell (the two authors of Principia Mathematica, as opposed to Newton's, which is titled simply, The Principia), and Karl Popper and Saul Kripke, both of whom have written numerous books on logic.
The series of points I wish to illustrate have to do with implicit categoric relations.
These relations can take place on a systemic, logical, or qualia basis. (In a non-variable sense the relations would be viewed more universally as system, mode, or value, where value can mean an abbreviation of an entire belief system, and mode can mean something existential).
Typically it is the systems that are original, whereas it is the qualia that are demonstrative. The logical level is arbitrary in the sense that multiple solutions are possible, and it avoids ambiguity through definitional quantification.
Now, the key element to deal with is an individual category, because it relates with all three levels simultaneously (qualific, logical, and systemic).
The key question is, 'What does a variable mean?' in relation to those three things, and I think I have found an answer. And there is a possibility that this work has been done before, without my realizing it. That is why I mentioned the other people before.
However, if my system in general is as unique as I tend to believe it is, then there is no reason to believe these other figures have dealt with the same observations, because they were not observing the same system...
On the qualia level, a category is an IFF (If-and-only-if) relation. That is, what is meant by a variable is little more than an indefinite relation. Sense-data, however irrational, is what fills in the gaps in information. And it requires the rational faculty to declare that there is justice to the information. Enough of that!
But, the IFF relation remains the way to engage with qualia data.
Logical relations on the other hand, occur through summation, and require additional analogies (such as assumptions or mathematics) to register an interpretation.
In terms of sense-data, logic consists of a summation of indefinite relations. Where the logic cannot be adduced to summation itself, some sort of correlative logic must be attached to ascribe meaning. The most common of these is a meaningful theory, such as a loaded assumption.
A system, then, tends to obey one of the following descriptions, and the same is true for systemic variables:
1. A pattern in data (a pattern amongst loaded assumptions), that is, a logic applied to a bad thesis.
2. In terms of sense-data, a summation of indefinite relations, that is, logic purum, and,
3. A summation and/or analogy based on the previous, that is, logic applied to logic.
Thus, 1/3 may be deemed incorrect, 1/3 may be deemed unprovable, and 1/3 may be deemed exponential.
That's what I have recently discovered about true variables.
Exceptions to the above may include variables which are not only non-qualified, but non-logical, and non-systematic.
The above is available as an academic paper HERE: https://www.academia.edu/16614178/_Variable_Calculus_or_Object-Oriented_Ontology
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