Search Results
Search type | Search syntax |
---|---|
Tags | [tag] |
Exact | "words here" |
Author |
user:1234 user:me (yours) |
Score |
score:3 (3+) score:0 (none) |
Answers |
answers:3 (3+) answers:0 (none) isaccepted:yes hasaccepted:no inquestion:1234 |
Views | views:250 |
Code | code:"if (foo != bar)" |
Sections |
title:apples body:"apples oranges" |
URL | url:"*.example.com" |
Saves | in:saves |
Status |
closed:yes duplicate:no migrated:no wiki:no |
Types |
is:question is:answer |
Exclude |
-[tag] -apples |
For more details on advanced search visit our help page |
A sort of definitionally proof-irrelevant propositions introduced in "Definitional Proof-Irrelevance without K" and implemented by Agda (as Prop) and Coq (as SProp).
6
votes
Why does it matter if canonicity holds for irrelevant types?
Consider the following type theory:
\begin{gather}
\frac{ }{\vdash G \; \mathsf{type}} \qquad
\frac{ }{\vdash \Lambda \; \mathsf{type}} \\[2ex]
\frac{\vdash g : G \qquad \vdash e_1 : \Lambda \qquad \v …
5
votes
Accepted
Pattern matching from `Prop` to `Type` in Lean
If $A : \mathsf{Prop}$ and $B : \mathsf{Type}$, then when defining a map $A \to B$ it is prohibited to match on the argument.
Why would anyone want this? … If we think of $A : \mathsf{Prop}$ as a logical statement then $a : A$ is like a proof, or evidence, that $A$ holds. …