Hackers' Pub

Syntax	Description	Examples
`"` keyword `"`	Finds the string within quotes, including spaces. Case-insensitive. (Escape quotes inside with `\"`)	`"Hackers' Pub"`
`from:` handle	Finds content written by the specified user.	`from:hongminhee` `from:hongminhee@hollo.social`
`lang:` ISO 639-1	Finds content written in the specified language.	`lang:en`
`#` tag	Finds content with the specified tag. Case-insensitive.	`#HackersPub`
condition condition	Finds content that satisfies both conditions on either side of the space (logical AND).	`"Hackers' Pub" lang:en`
condition `OR` condition	Finds content that satisfies at least one of the conditions on either side of the OR operator (logical OR).	`#HackersPub OR "Hackers' Pub" lang:en`
`(` condition `)`	Combines the operators within the parentheses first.	`(#HackersPub OR "Hackers' Pub" OR "Hackers Pub") lang:en`

José A. Alonso @Jose_A_Alonso@mathstodon.xyz

11/21/2025, 11:25:48 AM

Public

Formalization of derived categories in Lean/mathlib. ~ Joël Riou. https://afm.episciences.org/15978 #ITP #LeanProver

Formalisation des catégories dérives dans Lean/mathlib

Joël Riou · This paper outlines the formalization of derived categories in the mathematical library of the proof assistant Lean 4. The derived category D(C) of any abelian category C is formalized as the localization of the category of unbounded cochain complexes with respect to the class of quasi-isomorphisms, and it is endowed with a triangulated structure.

afm.episciences.org · Episciences

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