Examples
?- X is 2 ** 1.
X = 2
yes
?- X is 2 ** 2.
X = 4
yes
?- X is 2 ** 5.
X = 32
yes
?- X is 5 ** 3.
X = 125
yes
?- X is 5.0 ** 3.
X = 125.0
yes
?- X is 5 ** 3.0.
X = 125.0
yes
?- X is 5.0 ** 3.0.
X = 125.0
yes
?- X is 2 + 5 ** 3 - 1.
X = 126
yes
?- X is -2 ** 2.
X = 4
yesNote: in some Prolog implementations the result would be 0.25
?- X is -2 ** -2.
X = 0
yesNote: in some Prolog implementations the result would be 0.25
?- X is 2 ** -2.
X = 0
yes
?- X is 0.5 ** 2.
X = 0.25
yesNote: "^" is a synonym for "**".
?- X is 3^7.
X = 2187
yes