nLab
Brouwer-Heyting-Kolmogorov interpretation

natural deduction metalanguage, practical foundations

type theory (dependent, intensional, observational type theory, homotopy type theory)

logic	category theory	type theory
true	terminal object/(-2)-truncated object	h-level 0-type/unit type
false	initial object	empty type
proposition	(-1)-truncated object	h-level 1-type/h-prop
proof	generalized element	program
conjunction	product	product type
disjunction	coproduct ((-1)-truncation of)	sum type (bracket type of)
implication	internal hom	function type
negation	internal hom into initial object	function type into empty type
universal quantification	dependent product	dependent product type
existential quantification	dependent sum ((-1)-truncation of)	dependent sum type (bracket type of)
equivalence	path space object	identity type
equivalence class	quotient	quotient type
induction	colimit	inductive type, W-type, M-type
higher induction	higher colimit	higher inductive type
completely presented set	discrete object/0-truncated object	h-level 2-type/preset/h-set
set	internal 0-groupoid	Bishop set/setoid
universe	object classifier	type of types
modality	closure operator monad	modal type theory, monad (in computer science)

Idea

The Brouwer-Heyting-Kolmogorov interpretation of intuitionistic logic is a description of proofs of propositions in intuitionistic logic as functions, often computable functions?, where it is also called the realizability interpretation.

Wikipedia, BHK interpretation
J.-Y. Girard, Proofs and Types
A. Troelstra, History of Constructivism in the Twentieth Century (1991). (pdf)
Wouter Pieter Stekelenburg, Wouter Pieter Stekelenburg (arXiv:1301.2134)

Links to many papers on realizability and related topics may be found here.

For a comment see also

Revised on January 12, 2013 02:07:47 by Urs Schreiber (89.204.139.147)