Succeeds when the number argument X is equal to the number argument Y.
Examples
?- 1=:=1.
yes
?- 1.5=:=3.0/2.0.
yes
?- 6*6=:=9*4.
yes
?- 1=:=2.
no
?- 1+1=:=1-1.
no
?- X=1, Y=1, X=:=Y.
X = 1
Y = 1
yes
?- X=1, Y=2, X=:=Y.
no
?- 7.0=:=7.0.
yes
?- 7=:=7.0.
yes
?- 7.0=:=7.
yes
?- 7=:=7.
yes
?- 7.1=:=7.1.
yes
?- 7.0=:=7.1.
no
?- 7.1=:=7.2.
no
?- 7.2=:=7.1.
no
?- 7.1=:=7.
no
?- 7=:=7.1.
no
?- -7=:=-7.
yes
?- 7=:=-7.
no
?- -7=:=7.
no
?- 9223372036854775806 =:= 9223372036854775807.
no
?- 9223372036854775807 =:= 9223372036854775806.
no
?- 9223372036854775807 =:= 9223372036854775807.
yes
?- 9223372036854775806 =:= 9223372036854775806.
yes
?- -9223372036854775808 =:= -9223372036854775807.
no
?- -9223372036854775807 =:= -9223372036854775808.
no
?- -9223372036854775808 =:= -9223372036854775808.
yes
?- -9223372036854775807 =:= -9223372036854775807.
yesNote that due to loss of precision when comparing decimal fractions the following queries evaluate to true:
?- 9223372036854775806 =:= 9223372036854775807.0.
yes
?- 9223372036854775806.0 =:= 9223372036854775807.
yes
?- 9223372036854775806.0 =:= 9223372036854775807.0.
yes