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 of Contingent Propositions

I don’t know whether that helps any with but it does supply a lot of nice pictures to contemplate.

Resources

• Logical Graphs • One • Two
• Survey of Theme One Program
• Survey of Animated Logical Graphs
• Propositional Equation Reasoning Systems

cc: Cybernetics • Ontolog • Peirce List (1) (2) (3) • Structural Modeling • Systems Science