test
node1
BFO:0000003
occurrent
node1->node1
node3
BFO:0000015
process
node1->node3
node2
BFO:0000001
entity
node2->node1
node4
GO:0008150
biological_process
node3->node4
node5
GO:0032501
multicellular
organismal process
node4->node5
node6
GO:0001503
ossification
node5->node6
node7
GO:0036075
replacement
ossification
node6->node7