From 263ed462531df56321da91f97263589527e2420b Mon Sep 17 00:00:00 2001 From: Michael Zhang Date: Thu, 21 Sep 2023 17:40:43 -0500 Subject: [PATCH] time to bury this forever --- src/content/posts/2023-09-15-equality.md | 9 +++++++-- src/styles/_colors.scss | 3 ++- 2 files changed, 9 insertions(+), 3 deletions(-) diff --git a/src/content/posts/2023-09-15-equality.md b/src/content/posts/2023-09-15-equality.md index 40ba312..0cbabb2 100644 --- a/src/content/posts/2023-09-15-equality.md +++ b/src/content/posts/2023-09-15-equality.md @@ -23,13 +23,17 @@ to, since they're very different concepts. > > - Does $2$ equal $2$? Yes. This is the same object, and equality is reflexive. > - Does $s(s(z))$ equal $2$? Well, typically this is how natural numbers are - > defined in type systems: $2 \equiv s(s(z))$. _By definition_ they are - > identical. + > defined in type systems: $2 \equiv s(s(z))$. If somewhere before this, you + > said "let $2$ equal $s(s(z))$", then _by definition_ these are identical. > - Does $1 + 1$ equal $2$? The operation $+$ is a function, and requires a > β-reduction to evaluate any further. This choice really comes down to the > choice of the type theory designer; if you wanted a more intensional type > theory, you could choose to not allow β-reduction during evaluation of > identities. Most type theories _do_ allow this though. + > - Does $x = y$ for any $x$ and $y$? + > + > As far as I understand, you can choose whatever to _be_ your "definitional" + > equality, - **Propositional** equality. This describes a _value_ that potentially holds true or false. This is typically written $=$ in math. @@ -114,4 +118,5 @@ in your language too. In Agda, it's `Path {A} x y`. - https://ncatlab.org/nlab/show/definitional+equality - https://ncatlab.org/nlab/show/judgment - https://ncatlab.org/nlab/show/judgmental+equality +- https://ncatlab.org/nlab/show/propositional+equality - https://hott.github.io/book/hott-ebook.pdf.html diff --git a/src/styles/_colors.scss b/src/styles/_colors.scss index 7eb4af9..94c67e7 100644 --- a/src/styles/_colors.scss +++ b/src/styles/_colors.scss @@ -41,6 +41,7 @@ $backgroundColor: #202030; $textColor: #cdcdcd; $linkColor: lightskyblue; + $linkHoverColor: #202749; :root { --background-color: #{$backgroundColor}; @@ -53,7 +54,7 @@ --faded: #666; --hr-color: gray; --link-color: #{$linkColor}; - --link-hover-color: #{darken($linkColor, 60%)}; + --link-hover-color: #{$linkHoverColor}; --code-color: #{lighten(firebrick, 25%)}; --tag-color: #{darken($linkColor, 55%)};