This page describes currently proposed language for meta-descriptions. It may be updated frequently.
Standard relational operators apply
| Meaning | Operator |
| Less than | < |
| Less or equal | <= |
| Greater than | > |
| Greater or equal | >= |
| Equal | = |
|---|---|
| Different than | != |
Standard logical operators apply
| Meaning | Operator |
| And | and |
| Or | or |
| Xor | xor |
| Not | not |
For events in the timeline of events, using and or or operators denotes that any ordering between these events is possible.
Standard arithmetic operators apply and parenthesis are used for non-obvious precedence
We want to be able to denote order and concurrency of events and state changes, and duration of events.
| Meaning | Operator and example |
| A occurs after B | B -> A |
| A and B occur concurrently | A | | B |
| A lasts T time | AT |
| A occurs T time after B | B ->T A |
We want to be able to denote how many objects or events of a given type must/may occur.
| Meaning | Operator and example |
| Every object A | each A |
| Some objects A | some A |
| Some object A called a1 | some A a1 |
| A must occur | A |
| A may occur | [A] |
| Exactly N objects/events of type A | |A|N |
| At least N objects/events of type A | |A|>=N |
| At most N objects/events of type A | |A|<=N |