English
From IsField on a ring, one can equip the same set with a Field structure.
Русский
На том же множество можно снабдить структурой поля, если дано IsField.
LaTeX
$$$IsField\,R \Rightarrow Field\,R$$$
Lean4
/-- Transferring from `IsField` to `Field`. -/
noncomputable def toField {R : Type u} [Ring R] (h : IsField R) : Field R
where
__ :=
(‹Ring R› :) -- this also works without the `( :)`, but it's slow
__ := h.toSemifield
qsmul := _
qsmul_def := fun _ _ => rfl