Spacetime Diagram.
1	Spacetime	spacetime	NOUN	NN	Number=Sing	2	compound	2:compound	Discourse=organization-heading:122->123:2|Entity=(163-abstract-new-cf2-2-coref(1-abstract-giv:inact-cf1-1-coref)
2	Diagram	diagram	NOUN	NN	Number=Sing	0	root	0:root	Entity=163)|SpaceAfter=No
3	.	.	PUNCT	.	_	2	punct	2:punct	_
