Note about Mathlib/Init/
#
The files in Mathlib/Init
are leftovers from the port from Mathlib3.
(They contain content moved from lean3 itself that Mathlib needed but was not moved to lean4.)
We intend to move all the content of these files out into the main Mathlib
directory structure.
Contributions assisting with this are appreciated.
#align
statements without corresponding declarations
(i.e. because the declaration is in Batteries or Lean) can be left here.
These will be deleted soon so will not significantly delay deleting otherwise empty Init
files.
Orders #
Defines classes for preorders, partial orders, and linear orders and proves some basic lemmas about them.
A preorder is a reflexive, transitive relation ≤
with a < b
defined in the obvious way.
Instances
<
is decidable if ≤
is.
Equations
Instances For
Definition of PartialOrder
and lemmas about types with a partial order #
A partial order is a reflexive, transitive, antisymmetric relation ≤
.
Instances
Alias of le_antisymm
.
Equality is decidable if ≤
is.
Equations
Instances For
Definition of LinearOrder
and lemmas about types with a linear order #
This attempts to prove that a given instance of compare
is equal to compareOfLessAndEq
by
introducing the arguments and trying the following approaches in order:
- seeing if
rfl
works - seeing if the
compare
at hand is nonetheless essentiallycompareOfLessAndEq
, but, because of implicit arguments, requires us to unfold the defs and split theif
s in the definition ofcompareOfLessAndEq
- seeing if we can split by cases on the arguments, then see if the defs work themselves out
(useful when
compare
is defined via amatch
statement, as it is forBool
)
Equations
- tacticCompareOfLessAndEq_rfl = Lean.ParserDescr.node `tacticCompareOfLessAndEq_rfl 1024 (Lean.ParserDescr.nonReservedSymbol "compareOfLessAndEq_rfl" false)
Instances For
A linear order is reflexive, transitive, antisymmetric and total relation ≤
.
We assume that every linear ordered type has decidable (≤)
, (<)
, and (=)
.
- le : α → α → Prop
- lt : α → α → Prop
- le_refl : ∀ (a : α), a ≤ a
- min : α → α → α
- max : α → α → α
- compare : α → α → Ordering
A linear order is total.
- decidableLE : DecidableRel fun (x x_1 : α) => x ≤ x_1
In a linearly ordered type, we assume the order relations are all decidable.
- decidableEq : DecidableEq α
In a linearly ordered type, we assume the order relations are all decidable.
- decidableLT : DecidableRel fun (x x_1 : α) => x < x_1
In a linearly ordered type, we assume the order relations are all decidable.
The minimum function is equivalent to the one you get from
minOfLe
.The minimum function is equivalent to the one you get from
maxOfLe
.- compare_eq_compareOfLessAndEq : ∀ (a b : α), compare a b = compareOfLessAndEq a b
Comparison via
compare
is equal to the canonical comparison given decidable<
and=
.
Instances
A linear order is total.
The minimum function is equivalent to the one you get from minOfLe
.
The minimum function is equivalent to the one you get from maxOfLe
.
Comparison via compare
is equal to the canonical comparison given decidable <
and =
.
Equations
Equations
Equations
Equations
- ⋯ = ⋯
Equations
- ⋯ = ⋯
Equations
- ⋯ = ⋯
Equations
- ⋯ = ⋯