I am trying to work this out, not sure where to start even though the theorem appears intuitive! I thought I had proven it but then realised I has assumed the existance of an inverse!
For functions f,g and sets A, B
Given and and
where is the function
Then exists and
To show the exsistance of an inverse requires that f is a bijection? not sure how to derive that from what is given.
Thanks in advance!