English
There is an instance turning ArchimedeanClass(R) into a LinearOrderedAddCommGroupWithTop.
Русский
Существует экземпляр, превращающий ArchimedeanClass(R) в LinearOrderedAddCommGroupWithTop.
LaTeX
$$$\text{ArchimedeanClass}(R) \text{ admits a } \text{LinearOrderedAddCommGroupWithTop} \text{ structure.}$$$
Lean4
noncomputable instance : LinearOrderedAddCommGroupWithTop (ArchimedeanClass R)
where
neg_top := by simp [← mk_zero, ← mk_inv]
add_neg_cancel x
h :=
by
induction x with
| mk x
simp [← mk_inv, ← mk_mul, mul_inv_cancel₀ (mk_eq_top_iff.not.1 h)]
zsmul n x := n • x
zsmul_zero'
x := by
induction x with
| mk x => rw [← mk_zpow, zpow_zero, mk_one]
zsmul_succ' := zsmul_succ'
zsmul_neg' n
x :=
by
induction x with
| mk x
rw [← mk_zpow, zpow_negSucc, pow_succ, zsmul_succ', mk_inv, mk_mul, ← zpow_natCast, mk_zpow]