Algebraic structures on the set of positive numbers #
In this file we prove that the set of positive elements of a linear ordered field is a linear ordered commutative group.
@[implicit_reducible]
instance
Positive.Subtype.inv
{K : Type u_1}
[Field K]
[LinearOrder K]
[IsStrictOrderedRing K]
:
Inv { x : K // 0 < x }
@[simp]
theorem
Positive.coe_inv
{K : Type u_1}
[Field K]
[LinearOrder K]
[IsStrictOrderedRing K]
(x : { x : K // 0 < x })
:
@[implicit_reducible]
instance
Positive.instPowSubtypeLtOfNatInt_mathlib
{K : Type u_1}
[Field K]
[LinearOrder K]
[IsStrictOrderedRing K]
:
Pow { x : K // 0 < x } โค
@[simp]
theorem
Positive.coe_zpow
{K : Type u_1}
[Field K]
[LinearOrder K]
[IsStrictOrderedRing K]
(x : { x : K // 0 < x })
(n : โค)
:
โ(x ^ n) = โx ^ n
@[implicit_reducible]
instance
Positive.instCommGroupSubtypeLtOfNat
{K : Type u_1}
[Field K]
[LinearOrder K]
[IsStrictOrderedRing K]
: