max [3, 6, 9, 2]

max list == the smallest number that's larger than anything in the list

max [] = -infinity (the smallest available int)


min list == the largest number that's smaller than anything in the list

min [] = +infinity (the largest available int)


Notice that, for ANY integer value of x, we want
   Int.max( x, max [] ) ==> x
That means that max [] must be -infinity (the smallest available int).

And, for ANY integer value of x, we want
   Int.min( x, min [] ) ==> x
That means that min [] must be +infinity (the largest available int).