Spanda

Decision Conflict Resolution

Status: Stable — resolve_conflict() wired at runtime in interpreter tree evaluation.

When multiple layers produce competing decisions, Spanda applies a fixed precedence order.

Precedence (highest first)

1. Safety / kill switch — always wins
2. Local immediate safety — reflex layer reactions
3. Trust / security block — compromised or untrusted sources blocked
4. Human emergency override — operator e-stop and manual override
5. Control center policy — strategic governance
6. Fleet coordination — group-level reassignment and delegation
7. Local optimization — entity-level efficiency decisions

Example conflicts

Local robot	Fleet coordinator	Control center	Winner
Continue	Reassign	—	Fleet (unless safety/trust blocks)
Continue	—	Abort	Control center
E-stop	Continue	Continue	Safety reflex
Continue	Continue	—	Local (lowest precedence when no higher conflict)

API and engine

The resolve_conflict() function in spanda-decision applies precedence automatically. Rejected alternatives are recorded in DistributedDecisionRecord.rejected_alternatives.

Consensus vs conflict

Consensus (quorum, majority, trust-weighted voting) applies within Layer 2 for fleet/swarm agreement.

Conflict resolution applies across layers when decisions disagree.

Simulation

spanda decision simulate mission.sd --network-partition
spanda decision simulate mission.sd --fleet-coordinator-failure

Attack scenarios (spanda decision simulate-attack split_brain_coordinator) test split-brain handling via quorum and backup leader promotion.

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