What is this about? A pointer to a tutorial or a wiki link would be nice for someone who has no idea what this is. Thank you

It’s about term reduction in lambda calculus: https://en.wikipedia.org/wiki/Lambda_calculus#Reduction_stra...

Cosign, 10 hours in and comments are exclusively people who seemingly know each other already riffing on top of something that's not clear to an audience outside the community, or replying to a coarser version of request with ~0 information. (some tells: referring to other people by first name; having a 1:1 discussion about the meaning of a fork by some other person)