c.

_.

e.

n.

ne.

nw.

s.

se.

sw.

w.

edge.

graph.

node.

An Attr represents an attribute.

An AttrStmt represents an attribute statement.

An Edge represents an edge between two vertices.

An EdgeStmt represents an edge statement.

A File represents a DOT file.

A Graph represents a directed or an undirected graph.

A Node represents a node vertex.

A NodeStmt represents a node statement.

A Port specifies where on a node an edge should be aimed.

A Subgraph represents a subgraph vertex.

A Stmt represents a statement, and has one of the following underlying types.

A Vertex represents a vertex, and has one of the following underlying types.

CompassPoint specifies the set of compass points.

Kind specifies the set of graph components to which attribute statements may be assigned.