Category Archives: Model Theory

Re: Richard J. Lipton • Logical Complexity Of Proofs The smoothest way I know to do propositional calculus is by using minimal negation operators as primitives, parsing propositional formulas into (painted and rooted) cactus graphs, and using the appropriate extension … Continue reading →

Re: Ontolog Forum • John Sowa Re: Peirce List • John Sowa Dear John, I can’t imagine why anyone would bother with Peirce’s logic if it’s just Frege and Russell in a different syntax, which has been the opinion I … Continue reading →

A reader’s request for more examples of animated logical graphs prompted me to look again at the User Guide for my Theme One Program, whose exposition develops a series of logical graphs increasing in complexity from extremely simple to more substantial … Continue reading →

Re: R.J. Lipton and K.W. Regan • Proof Checking Dear Dick/Ken, Here’s a place where I explore different shapes of proofs in a propositional calculus deriving from the graphical systems of Charles S. Peirce and G. Spencer Brown. Propositional Equation Reasoning Systems • Analysis … Continue reading →

Re: Systems Science • Aleksandar Malečić Re: Animated Logical Graphs • 21 AM: Each step on its own, as far as I can follow them, makes sense.  You are, if I understand it correctly, trying to figure out something fundamental, … Continue reading →

The duality between Entitative and Existential interpretations of logical graphs is a good example of a mathematical symmetry, in this case a symmetry of order two.  Symmetries of this and higher orders give us conceptual handles on excess complexity in … Continue reading →

Re: Animated Logical Graphs • 21 Re: Ontolog Forum • Joseph Simpson JS: I tend to view equivalence and distinction as relationships as opposed to operations.  I do not know if this makes any significant difference in this context. Dear Joe, … Continue reading →

The rules given in the previous post for evaluating cactus graphs were given in purely formal terms, that is, by referring to the mathematical forms of cacti without mentioning their potential for logical meaning.  As it turns out, two ways … Continue reading →

This post and the next wrap up the Themes and Variations section of my speculation on Futures Of Logical Graphs.  I made an effort to “show my work”, reviewing the steps I took to arrive at the present perspective on … Continue reading →