`(graph-adjacent? (G <multidigraph>) u v [id])`method`(graph-adjacent? (G <multigraph>) u v [id])`method`(graph-adjacent? (G <digraph>) u v)`method`(graph-adjacent? (G <graph>) u v)`methodPredicate to check if an edge exists between vertices u and v (in other words, is v adjacent to u?). For multigraph types, an optional

`id`argument can also be passed, to differentiate between multiple edges.- G
- the graph to check
- u
- the head vertex
- v
- the tail vertex
- id
- an optional argument for multigraph-types which allows one to specify which edge you may be looking for (where
`id`is a unique identifier). Passing id when calling this method with a graph type will result in an error.