theorem instCoeObjectMaterialEntity._proof_1
theorem instCoeObjectMaterialEntity._proof_1: ∀ (v : qszr71sj.Object), qszr71sj.MaterialEntity.Is (Subtype.val v)
theorem instCoeObjectMaterialEntity._proof_1
theorem instCoeObjectMaterialEntity._proof_1: ∀ (v : qszr71sj.Object), qszr71sj.MaterialEntity.Is (Subtype.val v)