# </2

### Module: builtins

`</2`

— The left expression is less than the right expression

`>/2`

— The left expression is greater than the right expression

`=:=/2`

— The left and right expressions are equal

`=\=/2`

— The left and right expressions are not equal

`=</2`

— The left expression is less than or equal to the right

`>=/2`

— The left expression is greater than or equal to the right

## FORMS

```
Expression1 < Expression2
Expression1 > Expression2
Expression1 =:= Expression2
Expression1 =\= Expression2
Expression1 =< Expression2
Expression1 >= Expression2
```

## DESCRIPTION

Both arguments to each relational operator should be instantiated to expressions which can be evaluated by `is/2`

. The relational operator succeeds if the relation holds for the value of the two arguments, and fails otherwise. A relational operator will fail if one or both of its arguments cannot be evaluated.

## EXAMPLES

```
?- -7*0 =< 1+1
yes.
```

```
?- 1+1 =< 7*0
no.
```

## ERRORS

The ISO Prolog Standard requires that a calculation error be thrown when the arguments cannot be evaluated for any of these operators. At this time, ALS Prolog does not conform to this requirement. Instead, it throws a `type_error(evaluable,...)`

indicating that an argument is not evaluable.