| Select | *e*`.`*attrpath* \[ `or`*def* \] | Select attribute denoted by the attribute path *attrpath* from set *e*. (An attribute path is a dot-separated list of attribute names.) If the attribute doesn’t exist, return *def* if provided, otherwise abort evaluation. | none | 1 |
| Application | *e1**e2* | Call function *e1* with argument *e2*. | left | 2 |
| Update | *e1*`//`*e2* | Return a set consisting of the attributes in *e1* and *e2* (with the latter taking precedence over the former in case of equally named attributes). | right | 9 |
| Less Than | *e1*`<`*e2*, | Arithmetic/lexicographic comparison. | none | 10 |
| Less Than or Equal To | *e1*`<=`*e2* | Arithmetic/lexicographic comparison. | none | 10 |