LEAN_INFORMATION position 24:2 a b c d : ℕ, h₁ : a + b = 0, h₂ : b = 0, aeq0 : a = 0, h₃ : c + 1 + a = 1, h₄ : d = c - 1, deq0 : d = 0 ⊢ d = 0 END_LEAN_INFORMATION