## Relation


A relation, event or equivalence set over entities and relations.


Usage

``` python
Relation(
    *, type, members=(), trigger=None, id=None, attributes=None, metadata=None
)
```


## Attributes


`type: str`  
The relation or event type.

`members: tuple[Member, …]`  
The participants. Their order is kept but not significant for equality.

`trigger: str | None`  
ID of the entity whose text expresses the relation (event trigger, verb).

`id: str | None`  
Stable identifier; filled in by [Document](Document.md#cane_format.Document) when missing.


Equality uses type, trigger and members as a multiset. Symmetry needs no flag: members without distinguishing roles are interchangeable.