Lean4
instance divisionRing [DivisionRing α] : DivisionRing (ULift α)
where
toRing := ring
__ := groupWithZero
nnqsmul q x := up (DivisionSemiring.nnqsmul q x.down)
nnqsmul_def _ _ := congrArg up <| DivisionSemiring.nnqsmul_def _ _
nnratCast_def _ := congrArg up <| DivisionSemiring.nnratCast_def _
qsmul q x := up (DivisionRing.qsmul q x.down)
qsmul_def _ _ := congrArg up <| DivisionRing.qsmul_def _ _
ratCast_def _ := congrArg up <| DivisionRing.ratCast_def _