## Herman Geuvers ; Rob Nederpelt - Characteristics of de Bruijn's early proof checker Automath

fi:9343 - Fundamenta Informaticae, July 7, 2022, Volume 185, Issue 4
Characteristics of de Bruijn's early proof checker Automath

Authors: Herman Geuvers ; Rob Nederpelt

The mathematical language' Automath, conceived by N.G. de Bruijn in 1968, was the first theorem prover actually working and was used for checking many specimina of mathematical content. Its goals and syntactic ideas inspired Th. Coquand and G. Huet to develop the calculus of constructions, CC, which was one of the first widely used interactive theorem provers and forms the basis for the widely used Coq system. The original syntax of Automath is not easy to grasp. Yet, it is essentially based on a derivation system that is similar to the Calculus of Constructions (CC'). The relation between the Automath syntax and CC has not yet been sufficiently described, although there are many references in the type theory community to Automath. In this paper we focus on the backgrounds and on some uncommon aspects of the syntax of Automath. We expose the fundamental aspects of a `generic' Automath system, encapsulating the most common versions of Automath. We present this generic Automath system in a modern syntactic frame. The obtained system makes use of {\lambda}D, a direct extension of CC with definitions.

Volume: Volume 185, Issue 4
Published on: July 7, 2022
Accepted on: April 28, 2022
Submitted on: April 14, 2022
Keywords: Computer Science - Logic in Computer Science,Mathematics - Logic,68V15, 03B35,F.4