theorem instCoeDepTypeHistoryOfIs._proof_1
theorem instCoeDepTypeHistoryOfIs._proof_1: ∀ (x : Type) [qszr71sj.History.Is x], qszr71sj.History.Is x
theorem instCoeDepTypeHistoryOfIs._proof_1
theorem instCoeDepTypeHistoryOfIs._proof_1: ∀ (x : Type) [qszr71sj.History.Is x], qszr71sj.History.Is x