I was hoping that someone could give me some help with this inductive proof problem, I'm having a hard time understanding what to do.

Thanks in advance

For any nonempty setSlet ƒ :S Xlists(S) àN be defined by

ƒ(x,L) = ifL= <>then 0

else ifx= head(L) then 1 + ƒ(x, tail(L))

else ƒ(x, tail(L)).

Write out an induction proof that, "ƒ(x,L) is the number of occurrences ofx

inL."