On Fri, Oct 30, 2015 at 8:52 AM, Roelof Wobben wrote:

Let's say f is a recursive function which calculates the fac.

So f 0 = 0
f1 = 1
f2 = 2
f3 = 6

so im my oponion g1 = the answer of f1 which is also the max

But recall the problem definition:

4.21 Given a function f of type Integer -> Integer give a recursive definition of a
function of type Integer -> Integer which on input n returns the maximum
of the values f 0, f 1, ..., f n.

It doesn't say anything about f, which means you are not allowed to make assumptions about the definition of f.

f could be defined as:

f :: Integer -> Integer

f 42 = 100

f x = 0

Since you don't know anything about f, you must look at all values from f 0 to f n in order to find the maximum.

Regards,

Sean