The two DTSs are not equivalent.

DTS1 starts at dts1303a.xsd
DTS2 starts at dts1303b.xsd

The diff paths are:
???
[EvChange] ConceptA with ConceptA  
	[EvRelationshipFrom] general-special A -> B
	 [EvPrevious] general-special A -> B, in DTS2 previous is empty
	 [EvNext] On DTS1 next was empty, on DTS2 next is requires-element A -> B [EvArcrole]