Cf: Theme One Program • Discussion 8
http://inquiryintoinquiry.com/2022/06/27/theme-one-program-discussion-8/
Re: Ontolog Forum
https://groups.google.com/g/ontolog-forum/c/vlsQqvEiIkY
::: Alex Shkotin
https://groups.google.com/g/ontolog-forum/c/vlsQqvEiIkY/m/m2ESSeyeBQAJ
Re: Theme One Program • Exposition 4
https://inquiryintoinquiry.com/2022/06/20/theme-one-program-exposition-4/
Re: Logical Graphs • Animated Proofs
https://oeis.org/wiki/User:Jon_Awbrey/ANIMATION#Proof_Animations
<QUOTE AS:>
The animation is mesmerizing: I would watch and watch. But without
the pause, next frame, and playback speed settings, it's just a work
of art that calls to see it step by step.
And on page [1]
(
https://oeis.org/wiki/Propositional_Equation_Reasoning_Systems )
you start with the double negation theorem.
Have a look at a few of my comments as a reader, and only on the
graph topic taken separately. <...>
</QUOTE>
Dear Alex,
Thanks for viewing the animations and taking the time to work through that
first proof. Clearly a lot could be done to improve the production values —
what you see is what I got with whatever app I had umpteen years ago.
For the time being I'm focusing on the implementation layer of the
Theme One Program, which combines a learning component and a reasoning
component. The first implements a two‑level sequence learner and the
second implements a propositional calculator based on a variant of
Peirce's logical graphs. (I meant to say more about the learning
function this time around but I'm still working up to tackling that.)
To address your comments and questions we'll need to step back for a moment
to a more abstract, implementation-independent treatment of logical graphs.
There's a number of resources along those lines linked on the following
Survey page.
Survey of Animated Logical Graphs
https://inquiryintoinquiry.com/2021/05/01/survey-of-animated-logical-graphs…
The blog post “Logical Graphs • Formal Development”
(
https://inquiryintoinquiry.com/2008/09/19/logical-graphs-2/ )
gives a quick but systematic account of the formal system
I use throughout. The OEIS wiki article “Logical Graphs”
(
https://oeis.org/wiki/Logical_Graphs ) gives a more
detailed development.
Here's an excerpt from the above discussions, giving the four axioms
or “initials” which serve as graphical transformation rules, in effect,
the equational inference rules used to generate proofs and establish
theorems or “consequences”.
Axioms
======
The formal system of logical graphs is defined by a foursome of formal equations,
called “initials” when regarded purely formally, in abstraction from potential
interpretations, and called “axioms” when interpreted as logical equivalences.
There are two “arithmetic initials” and two “algebraic initials”, as shown below.
Arithmetic Initials
===================
Axiom I₁
https://inquiryintoinquiry.files.wordpress.com/2020/09/axiom-i1.png
Axiom I₂
https://inquiryintoinquiry.files.wordpress.com/2020/09/axiom-i2.png
Algebraic Initials
==================
Axiom J₁
https://inquiryintoinquiry.files.wordpress.com/2020/09/axiom-j1.png
Axiom J₂
https://inquiryintoinquiry.files.wordpress.com/2020/09/axiom-j2.png
The statement of the Double Negation Theorem is shown below.
C1. Double Negation Theorem
============================
The first theorem goes under the names of Consequence 1 (C₁),
the double negation theorem (DNT), or Reflection.
Double Negation Theorem
https://inquiryintoinquiry.files.wordpress.com/2021/02/double-negation-3.0.…
The following proof is adapted from the one given by George Spencer Brown
in his book Laws of Form and credited to two of his students, John Dawes
and D.A. Utting.
Double Negation Theorem • Proof
https://inquiryintoinquiry.files.wordpress.com/2021/02/double-negation-proo…
That should fill in enough background to get started on your questions …
Regards,
Jon