* Provided two types - provide all the relation possible between them.

type project{
    relation admin:  user 
}

[project,user]-> [admin] * provided one type & relation - provide all the type can be related provided type with the mentioned relation ship.

type project{
    relation admin:  user 
}

[project,admin ] -> [user] * provided source , target types and relation - provide all the relation/permission of target type can be associated here

type project{
    relation admin:  group#all_member  
}

[source : project, target : group , relation : admin ] ---> [all_member] At this point - no such API exist - correct ?