Contents Previous Next

• Fields Continued…
  • Fields
  • Ordered Fields

Fields Continued…

We now define objects of the field family, as we did for groups and rings before.

open import Agda.Primitive using (Level; _⊔_; lsuc; lzero)

open import Types.product
open import Types.relations
open import Types.equality

open import Algebra.order
open import Algebra.groups
open import Algebra.groups2
open import Algebra.rings
open import Algebra.rings2
open import Algebra.fields

module Algebra.fields2 where

Fields

record Field c ℓ : Set (lsuc (c ⊔ ℓ)) where
  infix  9 ÷_
  infix  8 -_
  infixl 7 _*_
  infixl 6 _+_
  infix  4 _≈_
  field
    Data     : Set c
    _≈_      : Rel Data ℓ
    _+_      : ★ Data
    _*_      : ★ Data
    -_       : ♠ Data
    ÷_       : ♠ Data
    0#       : Data
    1#       : Data
    isField  : IsField _≈_ _+_ _*_ -_ ÷_ 0# 1#

  open IsField isField public

  ring : Ring _ _
  ring = record { isRing = isRing }

  open Ring ring public
    using
    ( +-magma; +-semigroup; +-abelianGroup
    ; *-magma; *-semigroup
    ; +-monoid ; +-commutativeMonoid
    ; *-monoid
    ; nearSemiring; semiringWithoutOne; semiring
    ; semiringWithoutAnnihilatingZero
    )

Ordered Fields

record OrderedField c ℓ : Set (lsuc (c ⊔ ℓ)) where
  infix  9 ÷_
  infix  8 -_
  infixl 7 _*_
  infixl 6 _+_
  infix  4 _≈_
  field
    Data            : Set c
    _≈_             : Rel Data ℓ
    _≤_             : Rel Data ℓ
    _+_             : ★ Data
    _*_             : ★ Data
    -_              : ♠ Data
    ÷_              : ♠ Data
    0#              : Data
    1#              : Data
    isOrderedField  : IsOrderedField _≈_ _+_ _*_ -_ ÷_ _≤_ 0# 1#

  open IsOrderedField isOrderedField public

  ring : Ring _ _
  ring = record { isRing = isRing }

  open Ring ring public
    using
    ( +-magma; +-semigroup; +-abelianGroup
    ; *-magma; *-semigroup
    ; +-monoid ; +-commutativeMonoid
    ; *-monoid
    ; nearSemiring; semiringWithoutOne; semiring
    ; semiringWithoutAnnihilatingZero
    )

Numbers