B.5.RR:4.2 - Recover the dependence that matters

Begin at the changed premise and at the desired conclusion. Find which intermediate claims or constructions connect them. At each relevant transition, ask what is needed together, what is produced and why that transition is allowed.

Keep a sufficient alternative separately. For example, recovering a file may require either a readable local copy or an available remote copy. If both are encrypted with one unavailable key, the two storage locations leave the same prerequisite unresolved.

Use an established lemma at the level its receiving use needs. Open its proof when the change reaches a condition of the lemma or the way its result is obtained. Do the same for an established measurement or computation: inspect the part whose application the change calls into question.

A sketch or a few statements can hold these dependencies. Use B.1.1 when a dependency representation needs its relation clarified. A reasoning dependency says which premise or operation supports a conclusion; physical causation and temporal order require their own relations.

If the needed dependence is missing from the account, recover it through B.5.RA or ask for that contribution. Treat a supposedly unaffected part as reusable only when its independence from the change is adequately understood for this use.