Examples
?- X is 13 << 0.
X = 13
yes
?- X is 13 << 1.
X = 26
yes
?- X is 13 << 2.
X = 52
yes
?- X is 13 << 3.
X = 104
yes
?- X is 13 << 4.
X = 208
yesNote bit shifting using a negative value gives different results than in some other Prolog implementations.
?- X is 13 << -1.
X = -9223372036854775808
yes