So, this is 100% off-topic, but...could |A| signify the size of the (mathematical) set A, in a mathematics context?

And, yes, I am aware how way off-topic this is.

Yeah that should mean cardinality of the set A

thanks a million @dpsutton

Ask more math questions here!

ha, as they come up

I kinda spaced out for a bit, returned to the present with this tab open https://alvinalexander.com/scala/functional-programming-simplified-book. Not really sure how I got here. Anyone read it?