> ## 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.

# Monomer Selection

> How agents should choose BRIK64 monomers.

Use a core-first discipline when selecting monomers.

```text theme={null}
Try MC_00..MC_63 first.
Use MC_64..MC_127 only when behavior cannot be expressed cleanly with core monomers.
```

## Selection Steps

1. Identify the smallest operation needed.
2. Check whether a core monomer expresses it.
3. Prefer ordinary PCD control flow for branches.
4. Add extended monomer comments when extended behavior is required.
5. Do not invent helper functions or monomer names.

## Extended Candidate Comment

```pcd theme={null}
// certification-profile: extended_contract
// extended-monomers: MC_64 required for contract-bound float adapter
```

Extended monomer use creates a review item. It does not authorize a stronger public claim.