In a talk in Milan some time ago I claimed there were at least 8 different interpretations of a 2-in 2-out bitcoin transaction.

Today I was thinking about it and decided there were actually 15 in general :) And 52 different ways to make linkages in 5 inputs ... then I realised it was basically Bell numbers, which means there are 203 ways to make linkages in a 3-in 3-out. It scales exponentially.

Pinging @laurentmt because gists don't ping!

https://gist.github.com/LaurentMT/e758767ca4038ac40aaf#gistcomment-2851522

@laurentmt Pong

@waxwing Ping

@waxwing Note: just added a point about the scalability and composability of metrics

waxwing@waxwing@mastodon.socialAlso this problem is (I think) the same problem as how many rhyming schemes there are according to Wikipedia which is somehow a fun thought:

https://en.wikipedia.org/wiki/Bell_number#Rhyme_schemes