#snake lemma

[more-mathematics-mor-lam]

Sometimes a vision appears to you in class and you have to draw it

[mathhombre]

Snake Lemma

Kyle Ormsby was sharing with his topology class on Snake Lemma day. I'd never seen this!

[sometimesmyhandswork]

Guess who has forgotten all of their homological algebra

This is the Snake Lemma; if you have something of the shape of the dark grey commutative diagram and the rows are exact, then you can fill in the rest of the diagram. It's the map d that is usually of interest, and it's shape has led to the name Snake Lemma.

[woodsaddle]

this is the only realistic depiction of math in any movie i've ever seen. this is pretty much exactly how annoying math grad school is