theorem instCoeDepTypeMaterialEntityOfIs._proof_1
theorem instCoeDepTypeMaterialEntityOfIs._proof_1: ∀ (x : Type) [d4qbfhxh.MaterialEntity.Is x], d4qbfhxh.MaterialEntity.Is x
theorem instCoeDepTypeMaterialEntityOfIs._proof_1
theorem instCoeDepTypeMaterialEntityOfIs._proof_1: ∀ (x : Type) [d4qbfhxh.MaterialEntity.Is x], d4qbfhxh.MaterialEntity.Is x