---
title: 'lecture 03: categories, functors, natural transformations'
description: notes on lecture 3, drafted from 0 marks
date: '2026-10-13'
tags:
  - course
  - mit
created: '2026-10-13'
modified: '2026-10-13'
published: '2026-10-13'
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slug: courses/18.905-fall-2016/lectures/03
permalink: https://aarnphm.xyz/courses/18.905-fall-2016/lectures/03.md
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full: https://aarnphm.xyz/llms-full.txt
---
Source: [[courses/18.905-fall-2016/resources/mit18_905f16_lec3|lecture 3]].

## notes