Inverse

Many-to-one functions don't have inverses, by the definition of a function

>>8848647
If your range is a set of sets then they can. It's not strictly an inverse in the sense that composing it with the original yields an identity function but it doesn't matter for what I'm doing.

>>8848631
Set valued functions; they went out of fashion in the early 20th century.

https://en.wikipedia.org/wiki/Multivalued_function

>>8848661
> went out of fashion
Just to keep the language unambiguous?

>>8848661
Cheers

>>8848658
no.
if you consider it as an injective function f : X -> 2^X that's another story.

>>8848661
this terminology is retarded

Yeah the inverse image. If f:X -> Y

f^-1: Y -> P(X)

File: cosmos02_02.jpg (191KB, 800x389px) Image search: [Google]

191KB, 800x389px

What is this?

>>8848686
>that's another story
Wat. What makes a function with sets in its range not actually a function then? Seems to he no good reason for that. E.g. successor function for von Neumann numerals could not exist then.

>>8848715
"numerals"
fuck, ordinals*

You're basically looking for a quotient.