?- consult('gv2.pl').
true.

?- declare(a,10).
true.

?- declare(b,5).
true.

?- bindings.
a --> 10
b --> 5
true.

?- add(a,b,sum).
true.

?- bindings.
a --> 10
b --> 5
sum --> 15
true.

?- sub(a,b,difference).
true.

?- mul(a,b,product).
true.

?- div(a,b,quotient).
true.

?- pow(a,b,power).
true.

?- bindings
|    .
a --> 10
b --> 5
sum --> 15
difference --> 5
product --> 50
quotient --> 2
power --> 100000
true.

?- halt.