English
There is an open partial homeomorphism between 𝕜 and AddCircle p with source Ioo a (a+p) and target the complement of {a}.
Русский
Существует открытое частичное гомеоморфизм между 𝕜 и AddCircle p со sources Ioo a (a+p) и targetом дополнением {a}.
LaTeX
$$$$ \text{OpenPartialHomeomorph } 𝕜 \; (AddCircle\ p) $$$$
Lean4
theorem continuousAt_equivIco (hx : x ≠ a) : ContinuousAt (equivIco p a) x :=
by
induction x using QuotientAddGroup.induction_on
rw [ContinuousAt, Filter.Tendsto, QuotientAddGroup.nhds_eq, Filter.map_map]
exact (continuousAt_toIcoMod hp.out a hx).codRestrict _