A Syntactic Characterization of the Equality in Some Models for the Lambda Calculus

@article{Hyland1976ASC,
title={A Syntactic Characterization of the Equality in Some Models for the Lambda Calculus},
author={M. Hyland},
journal={Journal of The London Mathematical Society-second Series},
year={1976},
pages={361-370}
}

Journal of The London Mathematical Society-second Series

An equality relation on the terms of the A-calculus is an equivalence relation closed under the (syntactical) operations of application and A-abstraction. We may distinguish between syntactic and semantic ways of introducing equality relations, /^-equality is introduced syntactically; it is the least equality relation satisfying the equations for aand ^-conversion. For a more subtle way of introducing equality relations syntactically, consider the relations =f and =h of §5 of this paper. To… Expand