Ordered monoid and group homomorphisms #
This file defines morphisms between (additive) ordered monoids.
Types of morphisms #
OrderAddMonoidHom: Ordered additive monoid homomorphisms.OrderMonoidHom: Ordered monoid homomorphisms.OrderAddMonoidIso: Ordered additive monoid isomorphisms.OrderMonoidIso: Ordered monoid isomorphisms.
Notation #
→+o: Bundled ordered additive monoid homs. Also use for additive group homs.→*o: Bundled ordered monoid homs. Also use for group homs.≃+o: Bundled ordered additive monoid isos. Also use for additive group isos.≃*o: Bundled ordered monoid isos. Also use for group isos.
Implementation notes #
There's a coercion from bundled homs to fun, and the canonical notation is to use the bundled hom as a function via this coercion.
There is no OrderGroupHom -- the idea is that OrderMonoidHom is used.
The constructor for OrderMonoidHom needs a proof of map_one as well as map_mul; a separate
constructor OrderMonoidHom.mk' will construct ordered group homs (i.e. ordered monoid homs
between ordered groups) given only a proof that multiplication is preserved,
Implicit {} brackets are often used instead of type class [] brackets. This is done when the
instances can be inferred because they are implicit arguments to the type OrderMonoidHom. When
they can be inferred from the type it is faster to use this method than to use type class inference.
Removed typeclasses #
This file used to define typeclasses for order-preserving (additive) monoid homomorphisms:
OrderAddMonoidHomClass, OrderMonoidHomClass, and OrderMonoidWithZeroHomClass.
In https://github.com/leanprover-community/mathlib4/pull/10544 we migrated from these typeclasses
to assumptions like [FunLike F M N] [MonoidHomClass F M N] [OrderHomClass F M N],
making some definitions and lemmas irrelevant.
Tags #
ordered monoid, ordered group
α →+o β is the type of monotone functions α → β that preserve the OrderedAddCommMonoid
structure.
OrderAddMonoidHom is also used for ordered group homomorphisms.
When possible, instead of parametrizing results over (f : α →+o β),
you should parametrize over
(F : Type*) [FunLike F M N] [MonoidHomClass F M N] [OrderHomClass F M N] (f : F).
- toFun : α → β
- map_add' (x y : α) : (↑self.toAddMonoidHom).toFun (x + y) = (↑self.toAddMonoidHom).toFun x + (↑self.toAddMonoidHom).toFun y
- monotone' : Monotone (↑self.toAddMonoidHom).toFun
An
OrderAddMonoidHomis a monotone function.
Instances For
Infix notation for OrderAddMonoidHom.
Equations
- «term_→+o_» = Lean.ParserDescr.trailingNode `«term_→+o_» 25 26 (Lean.ParserDescr.binary `andthen (Lean.ParserDescr.symbol " →+o ") (Lean.ParserDescr.cat `term 25))
Instances For
α ≃+o β is the type of monotone isomorphisms α ≃ β that preserve the OrderedAddCommMonoid
structure.
OrderAddMonoidIso is also used for ordered group isomorphisms.
When possible, instead of parametrizing results over (f : α ≃+o β),
you should parametrize over
(F : Type*) [FunLike F M N] [AddEquivClass F M N] [OrderIsoClass F M N] (f : F).
- toFun : α → β
- invFun : β → α
- left_inv : Function.LeftInverse self.invFun self.toFun
- right_inv : Function.RightInverse self.invFun self.toFun
An
OrderAddMonoidIsorespects≤.
Instances For
Infix notation for OrderAddMonoidIso.
Equations
- «term_≃+o_» = Lean.ParserDescr.trailingNode `«term_≃+o_» 25 26 (Lean.ParserDescr.binary `andthen (Lean.ParserDescr.symbol " ≃+o ") (Lean.ParserDescr.cat `term 25))
Instances For
α →*o β is the type of functions α → β that preserve the OrderedCommMonoid structure.
OrderMonoidHom is also used for ordered group homomorphisms.
When possible, instead of parametrizing results over (f : α →*o β),
you should parametrize over
(F : Type*) [FunLike F M N] [MonoidHomClass F M N] [OrderHomClass F M N] (f : F).
- toFun : α → β
- map_mul' (x y : α) : (↑self.toMonoidHom).toFun (x * y) = (↑self.toMonoidHom).toFun x * (↑self.toMonoidHom).toFun y
- monotone' : Monotone (↑self.toMonoidHom).toFun
An
OrderMonoidHomis a monotone function.
Instances For
Infix notation for OrderMonoidHom.
Equations
- «term_→*o_» = Lean.ParserDescr.trailingNode `«term_→*o_» 25 26 (Lean.ParserDescr.binary `andthen (Lean.ParserDescr.symbol " →*o ") (Lean.ParserDescr.cat `term 25))
Instances For
Turn an element of a type F satisfying OrderHomClass F α β and MonoidHomClass F α β
into an actual OrderMonoidHom. This is declared as the default coercion from F to α →*o β.
Instances For
Turn an element of a type F satisfying OrderHomClass F α β and AddMonoidHomClass F α β
into an actual OrderAddMonoidHom.
This is declared as the default coercion from F to α →+o β.
Instances For
Any type satisfying OrderMonoidHomClass can be cast into OrderMonoidHom via
OrderMonoidHomClass.toOrderMonoidHom.
Any type satisfying OrderAddMonoidHomClass can be cast into OrderAddMonoidHom
via OrderAddMonoidHomClass.toOrderAddMonoidHom.
α ≃*o β is the type of isomorphisms α ≃ β that preserve the OrderedCommMonoid structure.
OrderMonoidIso is also used for ordered group isomorphisms.
When possible, instead of parametrizing results over (f : α ≃*o β),
you should parametrize over
(F : Type*) [FunLike F M N] [MulEquivClass F M N] [OrderIsoClass F M N] (f : F).
- toFun : α → β
- invFun : β → α
- left_inv : Function.LeftInverse self.invFun self.toFun
- right_inv : Function.RightInverse self.invFun self.toFun
An
OrderMonoidIsorespects≤.
Instances For
Infix notation for OrderMonoidIso.
Equations
- «term_≃*o_» = Lean.ParserDescr.trailingNode `«term_≃*o_» 25 26 (Lean.ParserDescr.binary `andthen (Lean.ParserDescr.symbol " ≃*o ") (Lean.ParserDescr.cat `term 25))
Instances For
Turn an element of a type F satisfying OrderIsoClass F α β and MulEquivClass F α β
into an actual OrderMonoidIso. This is declared as the default coercion from F to α ≃*o β.
Instances For
Turn an element of a type F satisfying OrderIsoClass F α β and AddEquivClass F α β
into an actual OrderAddMonoidIso.
This is declared as the default coercion from F to α ≃+o β.
Instances For
Any type satisfying OrderMonoidIsoClass can be cast into OrderMonoidIso via
OrderMonoidIsoClass.toOrderMonoidIso.
Any type satisfying OrderAddMonoidIsoClass can be cast into OrderAddMonoidIso
via OrderAddMonoidIsoClass.toOrderAddMonoidIso.
See also NonnegHomClass.apply_nonneg.
Equations
- OrderMonoidHom.instFunLike = { coe := fun (f : α →*o β) => (↑f.toMonoidHom).toFun, coe_injective' := ⋯ }
Equations
- OrderAddMonoidHom.instFunLike = { coe := fun (f : α →+o β) => (↑f.toAddMonoidHom).toFun, coe_injective' := ⋯ }
Reinterpret an ordered monoid homomorphism as an order homomorphism.
Equations
- f.toOrderHom = { toFun := (↑f.toMonoidHom).toFun, monotone' := ⋯ }
Instances For
Reinterpret an ordered additive monoid homomorphism as an order homomorphism.
Equations
- f.toOrderHom = { toFun := (↑f.toAddMonoidHom).toFun, monotone' := ⋯ }
Instances For
Copy of an OrderMonoidHom with a new toFun equal to the old one. Useful to fix
definitional equalities.
Instances For
Copy of an OrderAddMonoidHom with a new toFun equal to the old one. Useful to
fix definitional equalities.
Instances For
The identity map as an ordered monoid homomorphism.
Equations
- OrderMonoidHom.id α = { toMonoidHom := MonoidHom.id α, monotone' := ⋯ }
Instances For
The identity map as an ordered additive monoid homomorphism.
Equations
- OrderAddMonoidHom.id α = { toAddMonoidHom := AddMonoidHom.id α, monotone' := ⋯ }
Instances For
Equations
- OrderMonoidHom.instInhabited α = { default := OrderMonoidHom.id α }
Equations
- OrderAddMonoidHom.instInhabited α = { default := OrderAddMonoidHom.id α }
Composition of OrderMonoidHoms as an OrderMonoidHom.
Instances For
Composition of OrderAddMonoidHoms as an OrderAddMonoidHom
Instances For
1 is the homomorphism sending all elements to 1.
0 is the homomorphism sending all elements to 0.
For two ordered monoid morphisms f and g, their product is the ordered monoid morphism
sending a to f a * g a.
For two ordered additive monoid morphisms f and g, their product is the
ordered additive monoid morphism sending a to f a + g a.
Makes an ordered group homomorphism from a proof that the map preserves multiplication.
Equations
- OrderMonoidHom.mk' f hf map_mul = { toMonoidHom := MonoidHom.mk' f map_mul, monotone' := hf }
Instances For
Makes an ordered additive group homomorphism from a proof that the map preserves addition.
Equations
- OrderAddMonoidHom.mk' f hf map_mul = { toAddMonoidHom := AddMonoidHom.mk' f map_mul, monotone' := hf }
Instances For
The identity map as an ordered monoid isomorphism.
Equations
- OrderMonoidIso.refl α = { toMulEquiv := MulEquiv.refl α, map_le_map_iff' := ⋯ }
Instances For
The identity map as an ordered additive monoid isomorphism.
Equations
- OrderAddMonoidIso.refl α = { toAddEquiv := AddEquiv.refl α, map_le_map_iff' := ⋯ }
Instances For
Equations
- OrderMonoidIso.instInhabited α = { default := OrderMonoidIso.refl α }
Equations
- OrderAddMonoidIso.instInhabited α = { default := OrderAddMonoidIso.refl α }
Makes an ordered group isomorphism from a proof that the map preserves multiplication.
Equations
- OrderMonoidIso.mk' f hf map_mul = { toMulEquiv := MulEquiv.mk' f map_mul, map_le_map_iff' := ⋯ }
Instances For
Makes an ordered additive group isomorphism from a proof that the map preserves addition.
Equations
- OrderAddMonoidIso.mk' f hf map_mul = { toAddEquiv := AddEquiv.mk' f map_mul, map_le_map_iff' := ⋯ }