> ## Documentation Index
> Fetch the complete documentation index at: https://docs.brik64.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Parallel Composition

> EVA parallel composition.

Parallel composition describes independent branches.

In public PCD examples, represent parallel work as separate values with no shared mutation:

```pcd theme={null}
PC subtotal {
    fn subtotal(left: i64, right: i64) -> i64 {
        return MC_00.ADD8(left, right);
    }
}
```

## Review Points

* Branches use independent inputs.
* No branch mutates state needed by another branch.
* The merge step is explicit.
* The final result is named or returned.

## Review Guidance

Only describe branches as parallel when they do not depend on each other's intermediate state.