theorem instCoeObjectAggregateMaterialEntity._proof_1
theorem instCoeObjectAggregateMaterialEntity._proof_1: ∀ (v : d4qbfhxh.ObjectAggregate), d4qbfhxh.MaterialEntity.Is (Subtype.val v)
theorem instCoeObjectAggregateMaterialEntity._proof_1
theorem instCoeObjectAggregateMaterialEntity._proof_1: ∀ (v : d4qbfhxh.ObjectAggregate), d4qbfhxh.MaterialEntity.Is (Subtype.val v)