English
The inverse of restrictSupportEquiv applied to f yields f.extendDomain, i.e., the symm image corresponds to extending the domain.
Русский
ОбратноеRestrictSupportEquiv, применённое к f, даёт f.extendDomain; образ симм соответствует расширению области определения.
LaTeX
$$$(\\mathrm{restrictSupportEquiv}(s,M))^{-1} f = f.\\extendDomain$$$
Lean4
@[simp]
theorem restrictSupportEquiv_symm_apply_coe (s : Set α) (M : Type*) [AddCommMonoid M] [DecidablePred (· ∈ s)]
(f : s →₀ M) : (restrictSupportEquiv s M).symm f = f.extendDomain := by
rw [restrictSupportEquiv, Equiv.coe_fn_symm_mk, Subtype.coe_mk]; congr