English
If a is restricted by f to R and the quasispectrum of S a equals that of S b, then b with the same f is also restricted.
Русский
Если спектр квази-спектра a ограничен через f, и quasispectrum S a = quasispectrum S b, то ограничение распространяется на b.
LaTeX
$$$\\mathrm{QuasispectrumRestricts}(a,f) \\land (\\mathrm{quasispectrum}(S,a) = \\mathrm{quasispectrum}(S,b)) \\Rightarrow \\mathrm{QuasispectrumRestricts}(b,f)$$$
Lean4
theorem of_quasispectrum_eq {a b : A} {f : S → R} (ha : QuasispectrumRestricts a f)
(h : quasispectrum S a = quasispectrum S b) : QuasispectrumRestricts b f
where
rightInvOn := h ▸ ha.rightInvOn
left_inv := ha.left_inv