Documentation

Mathlib.Init.Data.Ordering.Lemmas

Some Ordering lemmas #

@[simp]
theorem Ordering.ite_eq_lt_distrib (c : Prop) [Decidable c] (a : Ordering) (b : Ordering) :
((if c then a else b) = Ordering.lt) = if c then a = Ordering.lt else b = Ordering.lt
@[simp]
theorem Ordering.ite_eq_eq_distrib (c : Prop) [Decidable c] (a : Ordering) (b : Ordering) :
((if c then a else b) = Ordering.eq) = if c then a = Ordering.eq else b = Ordering.eq
@[simp]
theorem Ordering.ite_eq_gt_distrib (c : Prop) [Decidable c] (a : Ordering) (b : Ordering) :
((if c then a else b) = Ordering.gt) = if c then a = Ordering.gt else b = Ordering.gt
@[simp]
theorem cmpUsing_eq_lt {α : Type u} {lt : ααProp} [DecidableRel lt] (a : α) (b : α) :
(cmpUsing lt a b = Ordering.lt) = lt a b
@[simp]
theorem cmpUsing_eq_gt {α : Type u} {lt : ααProp} [DecidableRel lt] [IsStrictOrder α lt] (a : α) (b : α) :
(cmpUsing lt a b = Ordering.gt) = lt b a
@[simp]
theorem cmpUsing_eq_eq {α : Type u} {lt : ααProp} [DecidableRel lt] (a : α) (b : α) :
(cmpUsing lt a b = Ordering.eq) = (¬lt a b ¬lt b a)