Arbitrage and Graphical Gridlock

The arbitrage-free law (or Kirchhoff’s voltage law) Recently I emailed a friend to complain when his organization used this 3 gear image as their logo. What was my complaint? Read on. The basic idea of arbitrage is to “get something for nothing” by trading commodities or currencies around some circle ending up with more than […]

From Partition Logic to Information Theory

A new logic of partitions has been developed that is dual to ordinary logic when the latter is interpreted as the logic of subsets rather than the logic of propositions. For a finite universe, the logic of subsets gave rise to finite probability theory by assigning to each subset its relative cardinality as a Laplacian probability. The analogous development for the dual logic of partitions gives rise to a notion of logical entropy that is related in a precise manner to Claude Shannon’s entropy.

Series-Parallel Duality: Part II: Financial arithmetic

In financial arithmetic and in the appraisal literature, it has been noticed that the basic formulas occur in pairs, one being the reciprocal of the other. This Part II of the series-parallel duality post shows that these reciprocal formulas are an example of the SP duality normally associated with electrical circuit theory.

The fatal flaw in finance theory: Capitalizing “goodwill”

The fatal flaw at the root of today’s post is really what might be called “the fundamental myth” about the current property system, namely that the market-contractual role of being the residual claimant in a productive opportunity is treated as a “property right” that is currently owned by some legal party (e.g., the corporation having the contractual role) and that may be bought and sold as well as capitalized into the party’s current valuation.

Series-Parallel Duality: Part I: Combating Series Chauvinism

This post describes the duality between the usual (series) addition and the dual parallel addition. This duality is normally considered in electrical circuit theory and combinatorics, but it has a much wider applications. In Part I of this post, the focus is on developing series-parallel dual formulas—in contrast to the usual focus on formulas using only the series sum.

The Math of Double-Entry Bookkeeping: Part I (scalars)

Double-entry bookkeeping illustrates one of the most astonishing examples of intellectual insulation between disciplines—the very opposite of intellectual trespassing.

The Math of Double-Entry Bookkeeping: Part II (vectors)

Although double-entry bookkeeping (DEB) has been used in the business world for 5 centuries, the mathematical formulation of the double entry method is almost completely unknown. The correct mathematical formulation allows the generalization from the value scalars of ordinary DEB to multi-dimensional accounting using vectors–which is the topic of this post.

Development or just poverty reduction?

Many of the debates about foreign aid and development assistance seem to pivot on different visions of the goal: development or just poverty reduction.

The implication operation on partitions

Partitions and equivalence relations In a 2001 commemorative volume for my mathematical mentor, Gian-Carlo Rota, three of his associates noted that “the only operations on the family of equivalence relations fully studied, understood and deployed are the binary join and meet operations.” This note defines the apparently new operation of implication for partitions, an operation […]

From propositional logic to subset logic to partition logic

From propositional logic to subset logic This note outlines the following sequence of ideas. First, ordinary propositional logic is reinterpreted as the logic of subsets of a universe set U, with the propositional case being isomorphic to the special case of U = 1. Then the category-theoretic duality between subsets of a set and partitions […]