English
If e: β ≃ α is a bijection and α is Primcodable, then the corresponding map e: β → α is Primrec.
Русский
Если e: β ≃ α — биекция и α примкодируем, то соответствующая функция e: β → α примрrec.
LaTeX
$$$$ \\mathrm{Primrec}(e) \\text{ for } e: \\beta \\xrightarrow{\\sim} \\alpha \\text{ (a bijection)} $$$$
Lean4
theorem of_equiv {β} {e : β ≃ α} :
haveI := Primcodable.ofEquiv α e
Primrec e :=
letI : Primcodable β := Primcodable.ofEquiv α e
encode_iff.1 Primrec.encode