19/04/20 21:56:35.50 E/H8FvM1.net
メモ
URLﾘﾝｸ(ncatlab.org)
ETCS
Context
Topos Theory
Foundations
Contents
1. Idea
2. Definition
3. A constructive view
4. A contemporary perspective
5. Todd Trimble’s exposition of ETCS
(抜粋)
1. Idea
The Elementary Theory of the Category of Sets , or ETCS for short, is an axiomatic formulation of set theory in a category-theoretic spirit. As such, it is the prototypical structural set theory. Proposed shortly after ETCC in (Lawvere 64) it is also the paradigm for a categorical foundation of mathematics.1
The theory intends to capture in an invariant way the notion of a (constant) ‘abstract set’ whose elements lack internal structure and whose on