transitive relation
binary relation R with the property that xRy and yRz implies xRz
subclass
class whose elements are all elements of a given other class
inclusion
concept that all the contents of one object are also contained within a second object
strict order
irreflexive transitive relation
transitive closure
operation on binary relations
coincidence
general phenomenon where distinct entities (such as regions of space, events, or sequences) exactly overlap in extent