Frederic Brenton Fitch was an American

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 logician, the inventor of Fitch-style calculus

Fitch-style calculus

Fitch-style calculus, also known as Fitch diagrams , is a method for constructing formal proofs used in first-order logic. It was invented by American logician Frederic Brenton Fitch...

, and a Sterling Professor Emeritus at Yale University

Yale University

Yale University is a private, Ivy League university located in New Haven, Connecticut, United States. Founded in 1701 in the Colony of Connecticut, the university is the third-oldest institution of higher education in the United States...

. In his 1963 published paper "A Logical Analysis of Some Value Concepts" he proves "Theorem 5" (originally by Alonzo Church

Alonzo Church

Alonzo Church was an American mathematician and logician who made major contributions to mathematical logic and the foundations of theoretical computer science. He is best known for the lambda calculus, Church–Turing thesis, Frege–Church ontology, and the Church–Rosser theorem.-Life:Alonzo Church...

) which later became famous in context of the Knowability Paradox

Fitch's paradox of knowability

Fitch's paradox of knowability is one of the fundamental puzzles of epistemic logic. It provides a challenge to the knowability thesis, which states that any truth is, in principle, knowable. The paradox is that this assumption implies the omniscience principle, which asserts that any truth is known...

.

Related

Stanford University

Stanford University

The Leland Stanford Junior University, commonly referred to as Stanford University or Stanford, is a private research university on an campus located near Palo Alto, California. It is situated in the northwestern Santa Clara Valley on the San Francisco Peninsula, approximately northwest of San...

 has produced an application called "Fitch".

An online Java application for proof building is also available http://logik.phl.univie.ac.at/~chris/gateway/formular-uk-fitch.html.

Publications

• "Symbolic Logic, An Introduction", The Ronald Press Company, 1952
• "A Logical Analysis of Some Value Concepts", The Journal of Symbolic Logic, 28, 1963
• "A Revision of Hohfeld's Theory of Legal Concepts", Logique et Analyse, 10, 1967

External links

• http://www.cc.utah.edu/~nahaj/logic/structures/systems/fitch.html
• http://plato.stanford.edu/entries/fitch-paradox/