Examples
?- X is max(5,5).
X = 5
yes
?- X is max(7,8).
X = 8
yes
?- X is max(3,2).
X = 3
yes
?- X is max(2.5,2.5).
X = 2.5
yes
?- X is max(2.75,2.5).
X = 2.75
yes
?- X is max(1,1.5).
X = 1.5
yes
?- X is max(2,1.5).
X = 2
yes
?- X is max(-3,2).
X = 2
yes
?- X is max(-3,-2).
X = -2
yes
?- X is max(-2.5,-2.25).
X = -2.25
yes
?- X is max(0,0).
X = 0
yes
?- X is max(0.0,0.0).
X = 0.0
yes
?- X is max(0,0.0).
X = 0.0
yes
?- X is max(0.0,0).
X = 0
yes