#SignRelationalManifolds • 3
• http://inquiryintoinquiry.com/2022/11/03/sign-relational-manifolds-3-2/

I'm not sure when it was I first noticed the relationship between #manifolds and #semiotics but I distinctly recall the passage in Serge Lang's Differential and Riemannian Manifolds (1995) which brought the triadic character of tangent vectors into high relief.

Excerpts from Lang's DARM

Chapter 2. Manifolds
2.1. #Atlases, #Charts, #Morphisms
• https://web.archive.org/web/20150302021003/http://stderr.org/pipermail/inquiry/2003-April/thread.html#442
2.2. #Submanifolds, #Immersions, #Submersions
• https://web.archive.org/web/20141220174800/http://stderr.org/pipermail/inquiry/2003-May/thread.html#448