# RefHashSet.isSubset

Check if this set is a subset of another.

## Signatures

```ts
export declare const isSubset: {
    <V>(that: HashSet.HashSet<V>): <E, R>(ref: RefHashSet<V, E, R>) => RefSubject.Computed<boolean, E, R>;
    <V, E, R>(ref: RefHashSet<V, E, R>, that: HashSet.HashSet<V>): RefSubject.Computed<boolean, E, R>;
};
```

## Why

Check if this set is a subset of another. The operation remains attached to the RefSubject's
versioned state boundary.

## Ownership and lifetime

The is subset view retains no independent state. An Effect read samples the source once; Fx
observation follows later pushes and its observing Scope owns subscription cleanup.