statements
   |---:default
   |   |---::=
   |   |---action
   |   |---=>
   |   |---[values]
   |---:start
   |   |---::=
   |   |---graph_grammar
   |---graph_grammar
   |   |---::=
   |   |---graph_definition
   |   |---action
   |   |---=>
   |   |---graph
   |---graph_definition
   |   |---::=
   |   |---node_definition
   |   |---|
   |   |---edge_definition
   |---node_definition
   |   |---::=
   |   |---node_statement
   |   |---|
   |   |---node_statement
   |   |---graph_definition
   |---node_statement
   |   |---::=
   |   |---node_name
   |   |---|
   |   |---node_name
   |   |---attribute_definition
   |   |---|
   |   |---node_statement
   |   |---(',')
   |   |---node_statement
   |---node_name
   |   |---::=
   |   |---start_node
   |   |---end_node
   |---:lexeme
   |   |---~
   |   |---start_node
   |   |---pause
   |   |---=>
   |   |---before
   |   |---event
   |   |---=>
   |   |---start_node
   |---start_node
   |   |---~
   |   |---'['
   |---:lexeme
   |   |---~
   |   |---end_node
   |---end_node
   |   |---~
   |   |---']'
   |---edge_definition
   |   |---::=
   |   |---edge_statement
   |   |---|
   |   |---edge_statement
   |   |---graph_definition
   |---edge_statement
   |   |---::=
   |   |---edge_name
   |   |---|
   |   |---edge_name
   |   |---attribute_definition
   |   |---|
   |   |---edge_statement
   |   |---(',')
   |   |---edge_statement
   |---edge_name
   |   |---::=
   |   |---directed_edge
   |   |---|
   |   |---undirected_edge
   |---:lexeme
   |   |---~
   |   |---directed_edge
   |   |---pause
   |   |---=>
   |   |---before
   |   |---event
   |   |---=>
   |   |---directed_edge
   |---directed_edge
   |   |---~
   |   |---'->'
   |---:lexeme
   |   |---~
   |   |---undirected_edge
   |   |---pause
   |   |---=>
   |   |---before
   |   |---event
   |   |---=>
   |   |---undirected_edge
   |---undirected_edge
   |   |---~
   |   |---'--'
   |---attribute_definition
   |   |---::=
   |   |---attribute_statement
   |---attribute_statement
   |   |---::=
   |   |---start_attributes
   |   |---end_attributes
   |---:lexeme
   |   |---~
   |   |---start_attributes
   |   |---pause
   |   |---=>
   |   |---before
   |   |---event
   |   |---=>
   |   |---start_attributes
   |---start_attributes
   |   |---~
   |   |---'{'
   |---:lexeme
   |   |---~
   |   |---end_attributes
   |---end_attributes
   |   |---~
   |   |---'}'
   |---:discard
   |   |---=>
   |   |---whitespace
   |---whitespace
       |---~
       |---[\s]
