Table 1

First version of the OBO Relation Ontology

Foundational relations

is_a

part_of

Spatial relations (connecting one entity to another in terms of relations between the spatial regions they occupy)

located_in

contained_in

adjacent_to

Temporal relations (connecting entities existing at different times)

transformation_of

derives_from

preceded_by

Participation relations (connecting processes to their bearers)

has_participant

has_agent

Smith et al. Genome Biology 2005 6:R46   doi:10.1186/gb-2005-6-5-r46