Partial Function. Having problems

[cooldog182]

Hi there,

I am having problems with this:

"Give an example of relations R and S such that S;RS is a partial function but R;S is not"

For a start, looking on the web or in numerous textbooks gives me a confused idea as to what a partial function really is.

Can anyone give me some insight perhaps? It would be very appreciated!

 

[pka]

"Give an example of relations R and S such that S;RS is a partial function but R;S is not" Can anyone give me some insight perhaps?

I have NO idea what means.
Please define both S;R and S;RS.
What is a partial function? I done this for a long time, but never saw that one.