Assertion: phalanx's base | /r/CapableOf | provide concave articulation
Facets:
value: with the metatarsal heads
type: OTHER
value: with the head
type: MANNER
Source sentences:
text: The two extremities are wider, with the base providing a concave articulation with the metatarsal heads and the head providing a convex articulation with the base of the middle phalanx (or distal phalanx in the case of the first toe).