ppProofs.lean:3:47-3:48: error: don't know how to synthesize placeholder context: α β : Sort u_1 b : β a : α h : α = β ⊢ h ▸ a = b ppProofs.lean:4:50-4:51: error: don't know how to synthesize placeholder context: α β : Sort u_1 b : β a : α h : α = β ⊢ (_ : α = β) ▸ a = b ppProofs.lean:5:50-5:57: error: unsolved goals α β : Sort ?u b : β a : α h : α = β ⊢ (_ : α = β) ▸ a = b ppProofs.lean:7:50-7:51: error: don't know how to synthesize placeholder context: α β : Sort u_1 b : β a : α h : α = β ⊢ _ ▸ a = b ppProofs.lean:9:50-9:51: error: don't know how to synthesize placeholder context: α β : Sort u_1 b : β a : α h : α = β ⊢ id h ▸ a = b