.. Help.


        if x > 0 , {x} ∩ ƒ(x-1)
ƒ(x) → <
        if x <= 0,  ø
Or

ƒ(x) → (0, x] ∩ N

Are these correct?

>>5
The two are only equivalent if you assume OP meant union instead of intersection and you take x to be in N. 

If you let x be in R, then f(4.3) = {4.3, 3.3, 2.2, 0.3} by the top definition, and {4, 3, 2) by the bottom.