case pos
α : Type u_1
inst✝¹ : PartialOrder α
inst✝ : SuccOrder α
a b : α
hb : IsMax b
⊢ a ≤ succ b ↔ a = succ b ∨ a ≤ b

case neg
α : Type u_1
inst✝¹ : PartialOrder α
inst✝ : SuccOrder α
a b : α
hb : ¬IsMax b
⊢ a ≤ succ b ↔ a = succ b ∨ a ≤ b
α : Type u_1
inst✝¹ : PartialOrder α
inst✝ : SuccOrder α
a b : α
⊢ a ≤ succ b ↔ a = succ b ∨ a ≤ b
by_cases hb : IsMax b
no goals
case pos
α : Type u_1
inst✝¹ : PartialOrder α
inst✝ : SuccOrder α
a b : α
hb : IsMax b
⊢ a ≤ succ b ↔ a = succ b ∨ a ≤ b
rw [hb.succ_eq, or_iff_right_of_imp le_of_eq]
no goals
case neg
α : Type u_1
inst✝¹ : PartialOrder α
inst✝ : SuccOrder α
a b : α
hb : ¬IsMax b
⊢ a ≤ succ b ↔ a = succ b ∨ a ≤ b
rw [← lt_succ_iff_of_not_isMax hb, le_iff_eq_or_lt]