rw [is_singular_point]
case neg
K : Type u
inst✝¹ : Field K
inst✝ : ECTate.PerfectRing K
e : Model K
h : discr e = 0
hc4 : ¬c4 e = 0
⊢ is_singular_point e ((18 * b6 e - b2 e * b4 e) / c4 e, (b2 e * b5 e + 3 * b7 e) / c4 e)
case neg
K : Type u
inst✝¹ : Field K
inst✝ : ECTate.PerfectRing K
e : Model K
h : discr e = 0
hc4 : ¬c4 e = 0
⊢ weierstrass e ((18 * b6 e - b2 e * b4 e) / c4 e, (b2 e * b5 e + 3 * b7 e) / c4 e) = 0 ∧
    dweierstrass_dx e ((18 * b6 e - b2 e * b4 e) / c4 e, (b2 e * b5 e + 3 * b7 e) / c4 e) = 0 ∧
      dweierstrass_dy e ((18 * b6 e - b2 e * b4 e) / c4 e, (b2 e * b5 e + 3 * b7 e) / c4 e) = 0