Documentation

Mathlib.Order.SuccPred.Limit

Successor and predecessor limits #

We define the predicate Order.IsSuccPrelimit for "successor pre-limits", values that don't cover any others. They are so named since they can't be the successors of anything smaller. We define Order.IsPredPrelimit analogously, and prove basic results.

For some applications, it is desirable to exclude minimal elements from being successor limits, or maximal elements from being predecessor limits. As such, we also provide Order.IsSuccLimit and Order.IsPredLimit, which exclude these cases.

TODO #

The plan is to eventually replace Ordinal.IsLimit and Cardinal.IsLimit with the common predicate Order.IsSuccLimit.

Successor limits #

def Order.IsSuccPrelimit {α : Type u_1} [LT α] (a : α) :

A successor pre-limit is a value that doesn't cover any other.

It's so named because in a successor order, a successor pre-limit can't be the successor of anything smaller.

Use IsSuccLimit if you want to exclude the case of a minimal element.

Equations
theorem Order.not_isSuccPrelimit_iff_exists_covBy {α : Type u_1} [LT α] (a : α) :
¬IsSuccPrelimit a ∃ (b : α), b a
@[simp]
theorem Order.IsSuccPrelimit.of_dense {α : Type u_1} [LT α] [DenselyOrdered α] (a : α) :
def Order.IsSuccLimit {α : Type u_1} [Preorder α] (a : α) :

A successor limit is a value that isn't minimal and doesn't cover any other.

It's so named because in a successor order, a successor limit can't be the successor of anything smaller.

This previously allowed the element to be minimal. This usage is now covered by IsSuccPrelimit.

Equations
theorem Order.IsSuccLimit.not_isMin {α : Type u_1} {a : α} [Preorder α] (h : IsSuccLimit a) :
theorem IsMin.not_isSuccLimit {α : Type u_1} {a : α} [Preorder α] (h : IsMin a) :
theorem IsMin.isSuccPrelimit {α : Type u_1} {a : α} [Preorder α] :
theorem Order.IsSuccLimit.ne_bot {α : Type u_1} {a : α} [Preorder α] [OrderBot α] (h : IsSuccLimit a) :
theorem Order.IsSuccPrelimit.isMax {α : Type u_1} {a : α} [Preorder α] [SuccOrder α] (h : IsSuccPrelimit (succ a)) :
theorem Order.IsSuccLimit.isMax {α : Type u_1} {a : α} [Preorder α] [SuccOrder α] (h : IsSuccLimit (succ a)) :
noncomputable def Order.IsSuccPrelimit.mid {α : Type u_1} [Preorder α] {i j : α} (hi : IsSuccPrelimit i) (hj : j < i) :
(Set.Ioo j i)

Given j < i with i a prelimit, IsSuccPrelimit.mid picks an arbitrary element strictly between j and i.

Equations
theorem Order.IsSuccPrelimit.succ_ne {α : Type u_1} {a : α} [Preorder α] [SuccOrder α] [NoMaxOrder α] (h : IsSuccPrelimit a) (b : α) :
succ b a
theorem Order.IsSuccLimit.succ_ne {α : Type u_1} {a : α} [Preorder α] [SuccOrder α] [NoMaxOrder α] (h : IsSuccLimit a) (b : α) :
succ b a
@[simp]
theorem Order.not_isSuccPrelimit_succ {α : Type u_1} [Preorder α] [SuccOrder α] [NoMaxOrder α] (a : α) :
@[simp]
theorem Order.not_isSuccLimit_succ {α : Type u_1} [Preorder α] [SuccOrder α] [NoMaxOrder α] (a : α) :
@[simp]
theorem Order.IsSuccLimit.bot_lt {α : Type u_1} {a : α} [PartialOrder α] [OrderBot α] (h : IsSuccLimit a) :
< a
theorem Order.isSuccPrelimit_of_succ_ne {α : Type u_1} {a : α} [PartialOrder α] [SuccOrder α] (h : ∀ (b : α), succ b a) :
theorem Order.not_isSuccPrelimit_iff {α : Type u_1} {a : α} [PartialOrder α] [SuccOrder α] :
¬IsSuccPrelimit a ∃ (b : α), ¬IsMax b succ b = a

See not_isSuccPrelimit_iff for a version that states that a is a successor of a value other than itself.

theorem Order.isSuccPrelimit_of_succ_lt {α : Type u_1} {b : α} [PartialOrder α] [SuccOrder α] (H : a < b, succ a < b) :
theorem Order.IsSuccPrelimit.succ_lt {α : Type u_1} {a b : α} [PartialOrder α] [SuccOrder α] (hb : IsSuccPrelimit b) (ha : a < b) :
succ a < b
theorem Order.IsSuccLimit.succ_lt {α : Type u_1} {a b : α} [PartialOrder α] [SuccOrder α] (hb : IsSuccLimit b) (ha : a < b) :
succ a < b
theorem Order.IsSuccPrelimit.succ_lt_iff {α : Type u_1} {a b : α} [PartialOrder α] [SuccOrder α] (hb : IsSuccPrelimit b) :
succ a < b a < b
theorem Order.IsSuccLimit.succ_lt_iff {α : Type u_1} {a b : α} [PartialOrder α] [SuccOrder α] (hb : IsSuccLimit b) :
succ a < b a < b
theorem Order.isSuccPrelimit_iff_succ_lt {α : Type u_1} {b : α} [PartialOrder α] [SuccOrder α] :
IsSuccPrelimit b a < b, succ a < b
theorem Order.isSuccPrelimit_iff_succ_ne {α : Type u_1} {a : α} [PartialOrder α] [SuccOrder α] [NoMaxOrder α] :
IsSuccPrelimit a ∀ (b : α), succ b a
@[simp]
@[simp]
theorem Order.not_isSuccLimit {α : Type u_1} {a : α} [PartialOrder α] [SuccOrder α] [IsSuccArchimedean α] :
theorem Order.IsSuccPrelimit.le_iff_forall_le {α : Type u_1} {a b : α} [LinearOrder α] (h : IsSuccPrelimit a) :
a b c < a, c b
theorem Order.IsSuccLimit.le_iff_forall_le {α : Type u_1} {a b : α} [LinearOrder α] (h : IsSuccLimit a) :
a b c < a, c b
theorem Order.IsSuccPrelimit.lt_iff_exists_lt {α : Type u_1} {a b : α} [LinearOrder α] (h : IsSuccPrelimit b) :
a < b c < b, a < c
theorem Order.IsSuccLimit.lt_iff_exists_lt {α : Type u_1} {a b : α} [LinearOrder α] (h : IsSuccLimit b) :
a < b c < b, a < c
theorem IsLUB.isSuccPrelimit_of_not_mem {α : Type u_1} {a : α} [LinearOrder α] {s : Set α} (hs : IsLUB s a) (ha : as) :
theorem IsLUB.mem_of_not_isSuccPrelimit {α : Type u_1} {a : α} [LinearOrder α] {s : Set α} (hs : IsLUB s a) (ha : ¬Order.IsSuccPrelimit a) :
a s
theorem IsLUB.isSuccLimit_of_not_mem {α : Type u_1} {a : α} [LinearOrder α] {s : Set α} (hs : IsLUB s a) (hs' : s.Nonempty) (ha : as) :
theorem IsLUB.mem_of_not_isSuccLimit {α : Type u_1} {a : α} [LinearOrder α] {s : Set α} (hs : IsLUB s a) (hs' : s.Nonempty) (ha : ¬Order.IsSuccLimit a) :
a s
theorem Order.IsSuccPrelimit.isLUB_Iio {α : Type u_1} {a : α} [LinearOrder α] (ha : IsSuccPrelimit a) :
theorem Order.IsSuccLimit.isLUB_Iio {α : Type u_1} {a : α} [LinearOrder α] (ha : IsSuccLimit a) :
theorem Order.IsSuccPrelimit.le_succ_iff {α : Type u_1} {a b : α} [LinearOrder α] [SuccOrder α] (hb : IsSuccPrelimit b) :
b succ a b a
theorem Order.IsSuccLimit.le_succ_iff {α : Type u_1} {a b : α} [LinearOrder α] [SuccOrder α] (hb : IsSuccLimit b) :
b succ a b a

Predecessor limits #

def Order.IsPredPrelimit {α : Type u_1} [LT α] (a : α) :

A predecessor pre-limit is a value that isn't covered by any other.

It's so named because in a predecessor order, a predecessor pre-limit can't be the predecessor of anything smaller.

Use IsPredLimit to exclude the case of a maximal element.

Equations
theorem Order.not_isPredPrelimit_iff_exists_covBy {α : Type u_1} [LT α] (a : α) :
¬IsPredPrelimit a ∃ (b : α), a b
@[simp]
theorem Order.IsPredPrelimit.of_dense {α : Type u_1} [LT α] [DenselyOrdered α] (a : α) :

Alias of the reverse direction of Order.isSuccPrelimit_toDual_iff.

Alias of the reverse direction of Order.isPredPrelimit_toDual_iff.

def Order.IsPredLimit {α : Type u_1} [Preorder α] (a : α) :

A predecessor limit is a value that isn't maximal and doesn't cover any other.

It's so named because in a predecessor order, a predecessor limit can't be the predecessor of anything larger.

This previously allowed the element to be maximal. This usage is now covered by IsPredPreLimit.

Equations
theorem Order.IsPredLimit.not_isMax {α : Type u_1} {a : α} [Preorder α] (h : IsPredLimit a) :
theorem Order.IsPredLimit.dual {α : Type u_1} {a : α} [Preorder α] :

Alias of the reverse direction of Order.isSuccLimit_toDual_iff.

theorem Order.IsSuccLimit.dual {α : Type u_1} {a : α} [Preorder α] :

Alias of the reverse direction of Order.isPredLimit_toDual_iff.

theorem IsMax.not_isPredLimit {α : Type u_1} {a : α} [Preorder α] (h : IsMax a) :
theorem IsMax.isPredPrelimit {α : Type u_1} {a : α} [Preorder α] :
theorem Order.IsPredLimit.ne_top {α : Type u_1} {a : α} [Preorder α] [OrderTop α] (h : IsPredLimit a) :
theorem Order.IsPredPrelimit.isMin {α : Type u_1} {a : α} [Preorder α] [PredOrder α] (h : IsPredPrelimit (pred a)) :
theorem Order.IsPredLimit.isMin {α : Type u_1} {a : α} [Preorder α] [PredOrder α] (h : IsPredLimit (pred a)) :
theorem Order.IsPredPrelimit.pred_ne {α : Type u_1} {a : α} [Preorder α] [PredOrder α] [NoMinOrder α] (h : IsPredPrelimit a) (b : α) :
pred b a
theorem Order.IsPredLimit.pred_ne {α : Type u_1} {a : α} [Preorder α] [PredOrder α] [NoMinOrder α] (h : IsPredLimit a) (b : α) :
pred b a
@[simp]
theorem Order.not_isPredPrelimit_pred {α : Type u_1} [Preorder α] [PredOrder α] [NoMinOrder α] (a : α) :
@[simp]
theorem Order.not_isPredLimit_pred {α : Type u_1} [Preorder α] [PredOrder α] [NoMinOrder α] (a : α) :
@[simp]
theorem Order.IsPredLimit.lt_top {α : Type u_1} {a : α} [PartialOrder α] [OrderTop α] (h : IsPredLimit a) :
a <
theorem Order.isPredPrelimit_of_pred_ne {α : Type u_1} {a : α} [PartialOrder α] [PredOrder α] (h : ∀ (b : α), pred b a) :
theorem Order.not_isPredPrelimit_iff {α : Type u_1} {a : α} [PartialOrder α] [PredOrder α] :
¬IsPredPrelimit a ∃ (b : α), ¬IsMin b pred b = a

See not_isPredPrelimit_iff for a version that states that a is a successor of a value other than itself.

theorem Order.isPredPrelimit_of_pred_lt {α : Type u_1} {a : α} [PartialOrder α] [PredOrder α] (H : b > a, a < pred b) :
theorem Order.IsPredPrelimit.lt_pred {α : Type u_1} {a b : α} [PartialOrder α] [PredOrder α] (ha : IsPredPrelimit a) (hb : a < b) :
a < pred b
theorem Order.IsPredLimit.lt_pred {α : Type u_1} {a b : α} [PartialOrder α] [PredOrder α] (ha : IsPredLimit a) (hb : a < b) :
a < pred b
theorem Order.IsPredPrelimit.lt_pred_iff {α : Type u_1} {a b : α} [PartialOrder α] [PredOrder α] (ha : IsPredPrelimit a) :
a < pred b a < b
theorem Order.IsPredLimit.lt_pred_iff {α : Type u_1} {a b : α} [PartialOrder α] [PredOrder α] (ha : IsPredLimit a) :
a < pred b a < b
theorem Order.isPredPrelimit_iff_lt_pred {α : Type u_1} {a : α} [PartialOrder α] [PredOrder α] :
IsPredPrelimit a b > a, a < pred b
theorem Order.isPredPrelimit_iff_pred_ne {α : Type u_1} {a : α} [PartialOrder α] [PredOrder α] [NoMinOrder α] :
IsPredPrelimit a ∀ (b : α), pred b a
@[simp]
@[simp]
theorem Order.not_isPredLimit {α : Type u_1} {a : α} [PartialOrder α] [PredOrder α] [IsPredArchimedean α] :
theorem Order.IsPredPrelimit.le_iff_forall_le {α : Type u_1} {a b : α} [LinearOrder α] (h : IsPredPrelimit a) :
b a ∀ ⦃c : α⦄, a < cb c
theorem Order.IsPredLimit.le_iff_forall_le {α : Type u_1} {a b : α} [LinearOrder α] (h : IsPredLimit a) :
b a ∀ ⦃c : α⦄, a < cb c
theorem Order.IsPredPrelimit.lt_iff_exists_lt {α : Type u_1} {a b : α} [LinearOrder α] (h : IsPredPrelimit b) :
b < a ∃ (c : α), b < c c < a
theorem Order.IsPredLimit.lt_iff_exists_lt {α : Type u_1} {a b : α} [LinearOrder α] (h : IsPredLimit b) :
b < a ∃ (c : α), b < c c < a
theorem IsGLB.isPredPrelimit_of_not_mem {α : Type u_1} {a : α} [LinearOrder α] {s : Set α} (hs : IsGLB s a) (ha : as) :
theorem IsGLB.mem_of_not_isPredPrelimit {α : Type u_1} {a : α} [LinearOrder α] {s : Set α} (hs : IsGLB s a) (ha : ¬Order.IsPredPrelimit a) :
a s
theorem IsGLB.isPredLimit_of_not_mem {α : Type u_1} {a : α} [LinearOrder α] {s : Set α} (hs : IsGLB s a) (hs' : s.Nonempty) (ha : as) :
theorem IsGLB.mem_of_not_isPredLimit {α : Type u_1} {a : α} [LinearOrder α] {s : Set α} (hs : IsGLB s a) (hs' : s.Nonempty) (ha : ¬Order.IsPredLimit a) :
a s
theorem Order.IsPredPrelimit.isGLB_Ioi {α : Type u_1} {a : α} [LinearOrder α] (ha : IsPredPrelimit a) :
theorem Order.IsPredLimit.isGLB_Ioi {α : Type u_1} {a : α} [LinearOrder α] (ha : IsPredLimit a) :
theorem Order.IsPredPrelimit.pred_le_iff {α : Type u_1} {a b : α} [LinearOrder α] [PredOrder α] (hb : IsPredPrelimit b) :
pred a b a b
theorem Order.IsPredLimit.pred_le_iff {α : Type u_1} {a b : α} [LinearOrder α] [PredOrder α] (hb : IsPredLimit b) :
pred a b a b

Induction principles #

noncomputable def Order.isSuccPrelimitRecOn {α : Type u_1} (b : α) {motive : αSort u_2} [PartialOrder α] [SuccOrder α] (succ : (a : α) → ¬IsMax amotive (succ a)) (isSuccPrelimit : (a : α) → IsSuccPrelimit amotive a) :
motive b

A value can be built by building it on successors and successor pre-limits.

Equations
theorem Order.isSuccPrelimitRecOn_of_isSuccPrelimit {α : Type u_1} {b : α} {motive : αSort u_2} [PartialOrder α] [SuccOrder α] (succ : (a : α) → ¬IsMax amotive (succ a)) (isSuccPrelimit : (a : α) → IsSuccPrelimit amotive a) (hb : IsSuccPrelimit b) :
isSuccPrelimitRecOn b succ isSuccPrelimit = isSuccPrelimit b hb
theorem Order.isSuccPrelimitRecOn_succ_of_not_isMax {α : Type u_1} {b : α} {motive : αSort u_2} [LinearOrder α] [SuccOrder α] (succ : (a : α) → ¬IsMax amotive (succ a)) (isSuccPrelimit : (a : α) → IsSuccPrelimit amotive a) (hb : ¬IsMax b) :
isSuccPrelimitRecOn (Order.succ b) succ isSuccPrelimit = succ b hb
@[simp]
theorem Order.isSuccPrelimitRecOn_succ {α : Type u_1} {motive : αSort u_2} [LinearOrder α] [SuccOrder α] (succ : (a : α) → ¬IsMax amotive (succ a)) (isSuccPrelimit : (a : α) → IsSuccPrelimit amotive a) [NoMaxOrder α] (b : α) :
isSuccPrelimitRecOn (Order.succ b) succ isSuccPrelimit = succ b
noncomputable def Order.isPredPrelimitRecOn {α : Type u_1} (b : α) {motive : αSort u_2} [PartialOrder α] [PredOrder α] (pred : (a : α) → ¬IsMin amotive (pred a)) (isPredPrelimit : (a : α) → IsPredPrelimit amotive a) :
motive b

A value can be built by building it on predecessors and predecessor pre-limits.

Equations
theorem Order.isPredPrelimitRecOn_of_isPredPrelimit {α : Type u_1} {b : α} {motive : αSort u_2} [PartialOrder α] [PredOrder α] (pred : (a : α) → ¬IsMin amotive (pred a)) (isPredPrelimit : (a : α) → IsPredPrelimit amotive a) (hb : IsPredPrelimit b) :
isPredPrelimitRecOn b pred isPredPrelimit = isPredPrelimit b hb
theorem Order.isPredPrelimitRecOn_pred_of_not_isMin {α : Type u_1} {b : α} {motive : αSort u_2} [LinearOrder α] [PredOrder α] (pred : (a : α) → ¬IsMin amotive (pred a)) (isPredPrelimit : (a : α) → IsPredPrelimit amotive a) (hb : ¬IsMin b) :
isPredPrelimitRecOn (Order.pred b) pred isPredPrelimit = pred b hb
@[simp]
theorem Order.isPredPrelimitRecOn_pred {α : Type u_1} {motive : αSort u_2} [LinearOrder α] [PredOrder α] (pred : (a : α) → ¬IsMin amotive (pred a)) (isPredPrelimit : (a : α) → IsPredPrelimit amotive a) [NoMinOrder α] (b : α) :
isPredPrelimitRecOn (Order.pred b) pred isPredPrelimit = pred b
noncomputable def Order.isSuccLimitRecOn {α : Type u_1} (b : α) {motive : αSort u_2} [PartialOrder α] [SuccOrder α] (isMin : (a : α) → IsMin amotive a) (succ : (a : α) → ¬IsMax amotive (succ a)) (isSuccLimit : (a : α) → IsSuccLimit amotive a) :
motive b

A value can be built by building it on minimal elements, successors, and successor limits.

Equations
@[simp]
theorem Order.isSuccLimitRecOn_of_isSuccLimit {α : Type u_1} {b : α} {motive : αSort u_2} [PartialOrder α] [SuccOrder α] (isMin : (a : α) → IsMin amotive a) (succ : (a : α) → ¬IsMax amotive (succ a)) (isSuccLimit : (a : α) → IsSuccLimit amotive a) (hb : IsSuccLimit b) :
isSuccLimitRecOn b isMin succ isSuccLimit = isSuccLimit b hb
theorem Order.isSuccLimitRecOn_succ_of_not_isMax {α : Type u_1} {b : α} {motive : αSort u_2} [LinearOrder α] [SuccOrder α] (isMin : (a : α) → IsMin amotive a) (succ : (a : α) → ¬IsMax amotive (succ a)) (isSuccLimit : (a : α) → IsSuccLimit amotive a) (hb : ¬IsMax b) :
isSuccLimitRecOn (Order.succ b) isMin succ isSuccLimit = succ b hb
@[simp]
theorem Order.isSuccLimitRecOn_succ {α : Type u_1} {motive : αSort u_2} [LinearOrder α] [SuccOrder α] (isMin : (a : α) → IsMin amotive a) (succ : (a : α) → ¬IsMax amotive (succ a)) (isSuccLimit : (a : α) → IsSuccLimit amotive a) [NoMaxOrder α] (b : α) :
isSuccLimitRecOn (Order.succ b) isMin succ isSuccLimit = succ b
theorem Order.isSuccLimitRecOn_of_isMin {α : Type u_1} {b : α} {motive : αSort u_2} [LinearOrder α] [SuccOrder α] (isMin : (a : α) → IsMin amotive a) (succ : (a : α) → ¬IsMax amotive (succ a)) (isSuccLimit : (a : α) → IsSuccLimit amotive a) (hb : IsMin b) :
isSuccLimitRecOn b isMin succ isSuccLimit = isMin b hb
noncomputable def Order.isPredLimitRecOn {α : Type u_1} (b : α) {motive : αSort u_2} [PartialOrder α] [PredOrder α] (isMax : (a : α) → IsMax amotive a) (pred : (a : α) → ¬IsMin amotive (pred a)) (isPredLimit : (a : α) → IsPredLimit amotive a) :
motive b

A value can be built by building it on maximal elements, predecessors, and predecessor limits.

Equations
@[simp]
theorem Order.isPredLimitRecOn_of_isPredLimit {α : Type u_1} {b : α} {motive : αSort u_2} [PartialOrder α] [PredOrder α] (isMax : (a : α) → IsMax amotive a) (pred : (a : α) → ¬IsMin amotive (pred a)) (isPredLimit : (a : α) → IsPredLimit amotive a) (hb : IsPredLimit b) :
isPredLimitRecOn b isMax pred isPredLimit = isPredLimit b hb
theorem Order.isPredLimitRecOn_pred_of_not_isMin {α : Type u_1} {b : α} {motive : αSort u_2} [LinearOrder α] [PredOrder α] (isMax : (a : α) → IsMax amotive a) (pred : (a : α) → ¬IsMin amotive (pred a)) (isPredLimit : (a : α) → IsPredLimit amotive a) (hb : ¬IsMin b) :
isPredLimitRecOn (Order.pred b) isMax pred isPredLimit = pred b hb
@[simp]
theorem Order.isPredLimitRecOn_pred {α : Type u_1} {b : α} {motive : αSort u_2} [LinearOrder α] [PredOrder α] (isMax : (a : α) → IsMax amotive a) (pred : (a : α) → ¬IsMin amotive (pred a)) (isPredLimit : (a : α) → IsPredLimit amotive a) [NoMinOrder α] :
isPredLimitRecOn (Order.pred b) isMax pred isPredLimit = pred b
theorem Order.isPredLimitRecOn_of_isMax {α : Type u_1} {b : α} {motive : αSort u_2} [LinearOrder α] [PredOrder α] (isMax : (a : α) → IsMax amotive a) (pred : (a : α) → ¬IsMin amotive (pred a)) (isPredLimit : (a : α) → IsPredLimit amotive a) (hb : IsMax b) :
isPredLimitRecOn b isMax pred isPredLimit = isMax b hb
noncomputable def SuccOrder.prelimitRecOn {α : Type u_1} (b : α) {motive : αSort u_2} [PartialOrder α] [SuccOrder α] [WellFoundedLT α] (succ : (a : α) → ¬IsMax amotive amotive (Order.succ a)) (isSuccPrelimit : (a : α) → Order.IsSuccPrelimit a((b : α) → b < amotive b)motive a) :
motive b

Recursion principle on a well-founded partial SuccOrder.

Equations
  • One or more equations did not get rendered due to their size.
@[simp]
theorem SuccOrder.prelimitRecOn_of_isSuccPrelimit {α : Type u_1} {b : α} {motive : αSort u_2} [PartialOrder α] [SuccOrder α] [WellFoundedLT α] (succ : (a : α) → ¬IsMax amotive amotive (Order.succ a)) (isSuccPrelimit : (a : α) → Order.IsSuccPrelimit a((b : α) → b < amotive b)motive a) (hb : Order.IsSuccPrelimit b) :
prelimitRecOn b succ isSuccPrelimit = isSuccPrelimit b hb fun (x : α) (x_1 : x < b) => prelimitRecOn x succ isSuccPrelimit
theorem SuccOrder.prelimitRecOn_succ_of_not_isMax {α : Type u_1} {b : α} {motive : αSort u_2} [LinearOrder α] [SuccOrder α] [WellFoundedLT α] (succ : (a : α) → ¬IsMax amotive amotive (Order.succ a)) (isSuccPrelimit : (a : α) → Order.IsSuccPrelimit a((b : α) → b < amotive b)motive a) (hb : ¬IsMax b) :
prelimitRecOn (Order.succ b) succ isSuccPrelimit = succ b hb (prelimitRecOn b succ isSuccPrelimit)
@[simp]
theorem SuccOrder.prelimitRecOn_succ {α : Type u_1} {motive : αSort u_2} [LinearOrder α] [SuccOrder α] [WellFoundedLT α] (succ : (a : α) → ¬IsMax amotive amotive (Order.succ a)) (isSuccPrelimit : (a : α) → Order.IsSuccPrelimit a((b : α) → b < amotive b)motive a) [NoMaxOrder α] (b : α) :
prelimitRecOn (Order.succ b) succ isSuccPrelimit = succ b (prelimitRecOn b succ isSuccPrelimit)
noncomputable def SuccOrder.limitRecOn {α : Type u_1} (b : α) {motive : αSort u_2} [PartialOrder α] [SuccOrder α] [WellFoundedLT α] (isMin : (a : α) → IsMin amotive a) (succ : (a : α) → ¬IsMax amotive amotive (Order.succ a)) (isSuccLimit : (a : α) → Order.IsSuccLimit a((b : α) → b < amotive b)motive a) :
motive b

Recursion principle on a well-founded partial SuccOrder, separating out the case of a minimal element.

Equations
  • One or more equations did not get rendered due to their size.
@[simp]
theorem SuccOrder.limitRecOn_isMin {α : Type u_1} {b : α} {motive : αSort u_2} [PartialOrder α] [SuccOrder α] [WellFoundedLT α] (isMin : (a : α) → IsMin amotive a) (succ : (a : α) → ¬IsMax amotive amotive (Order.succ a)) (isSuccLimit : (a : α) → Order.IsSuccLimit a((b : α) → b < amotive b)motive a) (hb : IsMin b) :
limitRecOn b isMin succ isSuccLimit = isMin b hb
@[simp]
theorem SuccOrder.limitRecOn_of_isSuccLimit {α : Type u_1} {b : α} {motive : αSort u_2} [PartialOrder α] [SuccOrder α] [WellFoundedLT α] (isMin : (a : α) → IsMin amotive a) (succ : (a : α) → ¬IsMax amotive amotive (Order.succ a)) (isSuccLimit : (a : α) → Order.IsSuccLimit a((b : α) → b < amotive b)motive a) (hb : Order.IsSuccLimit b) :
limitRecOn b isMin succ isSuccLimit = isSuccLimit b hb fun (x : α) (x_1 : x < b) => limitRecOn x isMin succ isSuccLimit
theorem SuccOrder.limitRecOn_succ_of_not_isMax {α : Type u_1} {b : α} {motive : αSort u_2} [LinearOrder α] [SuccOrder α] [WellFoundedLT α] (isMin : (a : α) → IsMin amotive a) (succ : (a : α) → ¬IsMax amotive amotive (Order.succ a)) (isSuccLimit : (a : α) → Order.IsSuccLimit a((b : α) → b < amotive b)motive a) (hb : ¬IsMax b) :
limitRecOn (Order.succ b) isMin succ isSuccLimit = succ b hb (limitRecOn b isMin succ isSuccLimit)
@[simp]
theorem SuccOrder.limitRecOn_succ {α : Type u_1} {motive : αSort u_2} [LinearOrder α] [SuccOrder α] [WellFoundedLT α] (isMin : (a : α) → IsMin amotive a) (succ : (a : α) → ¬IsMax amotive amotive (Order.succ a)) (isSuccLimit : (a : α) → Order.IsSuccLimit a((b : α) → b < amotive b)motive a) [NoMaxOrder α] (b : α) :
limitRecOn (Order.succ b) isMin succ isSuccLimit = succ b (limitRecOn b isMin succ isSuccLimit)
noncomputable def PredOrder.prelimitRecOn {α : Type u_1} (b : α) {motive : αSort u_2} [PartialOrder α] [PredOrder α] [WellFoundedGT α] (pred : (a : α) → ¬IsMin amotive amotive (Order.pred a)) (isPredPrelimit : (a : α) → Order.IsPredPrelimit a((b : α) → b > amotive b)motive a) :
motive b

Recursion principle on a well-founded partial PredOrder.

Equations
@[simp]
theorem PredOrder.prelimitRecOn_of_isPredPrelimit {α : Type u_1} {b : α} {motive : αSort u_2} [PartialOrder α] [PredOrder α] [WellFoundedGT α] (pred : (a : α) → ¬IsMin amotive amotive (Order.pred a)) (isPredPrelimit : (a : α) → Order.IsPredPrelimit a((b : α) → b > amotive b)motive a) (hb : Order.IsPredPrelimit b) :
prelimitRecOn b pred isPredPrelimit = isPredPrelimit b hb fun (x : α) (x_1 : x > b) => prelimitRecOn x pred isPredPrelimit
theorem PredOrder.prelimitRecOn_pred_of_not_isMin {α : Type u_1} {b : α} {motive : αSort u_2} [LinearOrder α] [PredOrder α] [WellFoundedGT α] (pred : (a : α) → ¬IsMin amotive amotive (Order.pred a)) (isPredPrelimit : (a : α) → Order.IsPredPrelimit a((b : α) → b > amotive b)motive a) (hb : ¬IsMin b) :
prelimitRecOn (Order.pred b) pred isPredPrelimit = pred b hb (prelimitRecOn b pred isPredPrelimit)
@[simp]
theorem PredOrder.prelimitRecOn_pred {α : Type u_1} {motive : αSort u_2} [LinearOrder α] [PredOrder α] [WellFoundedGT α] (pred : (a : α) → ¬IsMin amotive amotive (Order.pred a)) (isPredPrelimit : (a : α) → Order.IsPredPrelimit a((b : α) → b > amotive b)motive a) [NoMinOrder α] (b : α) :
prelimitRecOn (Order.pred b) pred isPredPrelimit = pred b (prelimitRecOn b pred isPredPrelimit)
noncomputable def PredOrder.limitRecOn {α : Type u_1} (b : α) {motive : αSort u_2} [PartialOrder α] [PredOrder α] [WellFoundedGT α] (isMax : (a : α) → IsMax amotive a) (pred : (a : α) → ¬IsMin amotive amotive (Order.pred a)) (isPredLimit : (a : α) → Order.IsPredLimit a((b : α) → b > amotive b)motive a) :
motive b

Recursion principle on a well-founded partial PredOrder, separating out the case of a maximal element.

Equations
@[simp]
theorem PredOrder.limitRecOn_isMax {α : Type u_1} {b : α} {motive : αSort u_2} [PartialOrder α] [PredOrder α] [WellFoundedGT α] (isMax : (a : α) → IsMax amotive a) (pred : (a : α) → ¬IsMin amotive amotive (Order.pred a)) (isPredLimit : (a : α) → Order.IsPredLimit a((b : α) → b > amotive b)motive a) (hb : IsMax b) :
limitRecOn b isMax pred isPredLimit = isMax b hb
@[simp]
theorem PredOrder.limitRecOn_of_isPredLimit {α : Type u_1} {b : α} {motive : αSort u_2} [PartialOrder α] [PredOrder α] [WellFoundedGT α] (isMax : (a : α) → IsMax amotive a) (pred : (a : α) → ¬IsMin amotive amotive (Order.pred a)) (isPredLimit : (a : α) → Order.IsPredLimit a((b : α) → b > amotive b)motive a) (hb : Order.IsPredLimit b) :
limitRecOn b isMax pred isPredLimit = isPredLimit b hb fun (x : α) (x_1 : x > b) => limitRecOn x isMax pred isPredLimit
theorem PredOrder.limitRecOn_pred_of_not_isMin {α : Type u_1} {b : α} {motive : αSort u_2} [LinearOrder α] [PredOrder α] [WellFoundedGT α] (isMax : (a : α) → IsMax amotive a) (pred : (a : α) → ¬IsMin amotive amotive (Order.pred a)) (isPredLimit : (a : α) → Order.IsPredLimit a((b : α) → b > amotive b)motive a) (hb : ¬IsMin b) :
limitRecOn (Order.pred b) isMax pred isPredLimit = pred b hb (limitRecOn b isMax pred isPredLimit)
@[simp]
theorem PredOrder.limitRecOn_pred {α : Type u_1} {motive : αSort u_2} [LinearOrder α] [PredOrder α] [WellFoundedGT α] (isMax : (a : α) → IsMax amotive a) (pred : (a : α) → ¬IsMin amotive amotive (Order.pred a)) (isPredLimit : (a : α) → Order.IsPredLimit a((b : α) → b > amotive b)motive a) [NoMinOrder α] (b : α) :
limitRecOn (Order.pred b) isMax pred isPredLimit = pred b (limitRecOn b isMax pred isPredLimit)