∀ (d : ℤ) (p₁ p₂ p₃ : Int.Linear.Poly),
  Int.Linear.dvd_le_tight_cert d p₁ p₂ p₃ =
    (Int.blt' 0 d).and'
      ((p₂.beq' ((p₁.addConst_k (-p₁.getConst)).addConst_k p₂.getConst)).and'
        (p₃.beq' ((p₁.addConst_k (-p₁.getConst)).addConst_k (p₁.getConst - d * ((p₁.getConst - p₂.getConst) / d)))))