English
The underlying group of a topological additive torsor is a topological group.
Русский
Вещественная группа тора‑массивной структуры имеет топологическую группу.
LaTeX
$$$ IsTopologicalAddGroup V $$$
Lean4
/-- The underlying group of a topological torsor is a topological group. This is not an instance, as
`P` cannot be inferred. -/
theorem to_isTopologicalAddGroup : IsTopologicalAddGroup V
where
continuous_add := by
have ⟨p⟩ : Nonempty P := inferInstance
conv =>
enter [1, x]
equals (x.1 +ᵥ x.2 +ᵥ p) -ᵥ p => rw [vadd_vadd, vadd_vsub]
fun_prop
continuous_neg := by
have ⟨p⟩ : Nonempty P := inferInstance
conv =>
enter [1, v]
equals p -ᵥ (v +ᵥ p) => rw [vsub_vadd_eq_vsub_sub, vsub_self, zero_sub]
fun_prop