Unbundled relation classes #
In this file we prove some properties of Is*
classes defined in Mathlib.Order.Defs
. The main
difference between these classes and the usual order classes (Preorder
etc) is that usual classes
extend LE
and/or LT
while these classes take a relation as an explicit argument.
A version of antisymm
with r
explicit.
This lemma matches the lemmas from lean core in Init.Algebra.Classes
, but is missing there.
A version of antisymm'
with r
explicit.
This lemma matches the lemmas from lean core in Init.Algebra.Classes
, but is missing there.
In a trichotomous irreflexive order, every element is determined by the set of predecessors.
Construct a partial order from an isStrictOrder
relation.
See note [reducible non-instances].
Equations
Instances For
Construct a linear order from an IsStrictTotalOrder
relation.
See note [reducible non-instances].
Equations
- linearOrderOfSTO r = LinearOrder.mk ⋯ (fun (x y : α) => decidable_of_iff (¬r y x) ⋯) decidableEqOfDecidableLE decidableLTOfDecidableLE ⋯ ⋯ ⋯
Instances For
Order connection #
A connected order is one satisfying the condition a < c → a < b ∨ b < c
.
This is recognizable as an intuitionistic substitute for a ≤ b ∨ b ≤ a
on
the constructive reals, and is also known as negative transitivity,
since the contrapositive asserts transitivity of the relation ¬ a < b
.
- conn (a b c : α) : lt a c → lt a b ∨ lt b c
A connected order is one satisfying the condition
a < c → a < b ∨ b < c
.
Instances
Well-order #
A well-founded relation. Not to be confused with IsWellOrder
.
- wf : WellFounded r
The relation is
WellFounded
, as a proposition.
Instances
The lexicographical order of well-founded relations is well-founded.
Alias of WellFounded.psigma_lex
.
The lexicographical order of well-founded relations is well-founded.
Alias of WellFounded.psigma_revLex
.
Alias of WellFounded.psigma_skipLeft
.
Induction on a well-founded relation.
All values are accessible under the well-founded relation.
Creates data, given a way to generate a value from all that compare as less under a well-founded
relation. See also IsWellFounded.fix_eq
.
Equations
- IsWellFounded.fix r = ⋯.fix
Instances For
The value from IsWellFounded.fix
is built from the previous ones as specified.
Derive a WellFoundedRelation
instance from an isWellFounded
instance.
Equations
- IsWellFounded.toWellFoundedRelation r = { rel := r, wf := ⋯ }
Instances For
A class for a well founded relation <
.
Equations
- WellFoundedLT α = IsWellFounded α fun (x1 x2 : α) => x1 < x2
Instances For
A class for a well founded relation >
.
Equations
- WellFoundedGT α = IsWellFounded α fun (x1 x2 : α) => x1 > x2
Instances For
A well order is a well-founded linear order.
- wf : WellFounded r
Instances
Inducts on a well-founded <
relation.
All values are accessible under the well-founded <
.
Creates data, given a way to generate a value from all that compare as lesser. See also
WellFoundedLT.fix_eq
.
Equations
- WellFoundedLT.fix = IsWellFounded.fix fun (x1 x2 : α) => x1 < x2
Instances For
The value from WellFoundedLT.fix
is built from the previous ones as specified.
Derive a WellFoundedRelation
instance from a WellFoundedLT
instance.
Equations
- WellFoundedLT.toWellFoundedRelation = IsWellFounded.toWellFoundedRelation fun (x1 x2 : α) => x1 < x2
Instances For
Inducts on a well-founded >
relation.
All values are accessible under the well-founded >
.
Creates data, given a way to generate a value from all that compare as greater. See also
WellFoundedGT.fix_eq
.
Equations
- WellFoundedGT.fix = IsWellFounded.fix fun (x1 x2 : α) => x1 > x2
Instances For
The value from WellFoundedGT.fix
is built from the successive ones as specified.
Derive a WellFoundedRelation
instance from a WellFoundedGT
instance.
Equations
- WellFoundedGT.toWellFoundedRelation = IsWellFounded.toWellFoundedRelation fun (x1 x2 : α) => x1 > x2
Instances For
Construct a decidable linear order from a well-founded linear order.
Equations
Instances For
Derive a WellFoundedRelation
instance from an IsWellOrder
instance.
Instances For
See Prod.wellFoundedLT
for a version that only requires Preorder α
.
See Prod.wellFoundedGT
for a version that only requires Preorder α
.
A bounded or final set. Not to be confused with Bornology.IsBounded
.
Equations
- Set.Bounded r s = ∃ (a : α), ∀ (b : α), b ∈ s → r b a
Instances For
Strict-non strict relations #
An unbundled relation class stating that r
is the nonstrict relation corresponding to the
strict relation s
. Compare Preorder.lt_iff_le_not_le
. This is mostly meant to provide dot
notation on (⊆)
and (⊂)
.
The relation
r
is the nonstrict relation corresponding to the strict relations
.
Instances
A version of right_iff_left_not_left
with explicit r
and s
.
⊆
and ⊂
#
Alias of subset_of_eq_of_subset
.
Alias of subset_of_subset_of_eq
.
Alias of subset_of_eq
.
Alias of superset_of_eq
.
Alias of subset_trans
.
Alias of subset_antisymm
.
Alias of superset_antisymm
.
Alias of ssubset_of_eq_of_ssubset
.
Alias of ssubset_of_ssubset_of_eq
.
Alias of ssubset_irrfl
.
Alias of ne_of_ssubset
.
Alias of ne_of_ssuperset
.
Alias of ssubset_trans
.
Alias of ssubset_asymm
.
Alias of subset_of_ssubset
.
Alias of not_subset_of_ssubset
.
Alias of not_ssubset_of_subset
.
Alias of ssubset_of_subset_not_subset
.
Alias of ssubset_of_subset_of_ssubset
.
Alias of ssubset_of_ssubset_of_subset
.
Alias of ssubset_of_subset_of_ne
.
Alias of ssubset_of_ne_of_subset
.
Alias of eq_or_ssubset_of_subset
.
Alias of ssubset_or_eq_of_subset
.
Alias of eq_of_subset_of_not_ssubset
.
Alias of eq_of_superset_of_not_ssuperset
.