# Structure Operations

## Related Structures

### `Category(V): RngVal -> Cat`

### `Parent(V): RngVal -> Pow`

### `PrimeRing(V): RngVal -> RngVal`

### `Center(V): RngVal -> RngVal`

### `FieldOfFractions(V): RngVal -> Rng`

Return field of fractions of the valuation ring $V$, which is the rational field or the function field from which $V$ was created.

## Numerical Invariants

### `Characteristic(V): RngVal -> RngIntElt`