The SFT Core

SoftwareField and architecture projection

`SoftwareField` is a computable slice of a development field. It is not itself an AAT `ArchitectureObject`; the AAT object is obtained through architecture projection.

arch : SoftwareField -> ArchitectureObject

ComputableCore
  = SoftwareField
  + arch projection
  + ArtifactMediatedChange
  + OperationSupport
  + OperationPolicy
  + StepRelation
  + ObservationRecord
  + GovernanceIntervention
  + ForecastCone
  + FieldUpdate

• Contextual state History, constraints, observations, governance, and exogenous artifact inputs belong to the field.
• Architecture projection AAT reasoning applies to the projected architecture object, not to every field component at once.

Artifact-mediated change

The formal term is `ArtifactAction` or `ArtifactMediatedChange`. Force remains an informal field-level reading. PRDs, specs, issues, and AI proposals can produce multiple candidate updates rather than a single next field.

ArtifactAction a
  := alpha_a : FieldSpace -> Set FieldSpaceUpdateHypothesis

Forecasted effects are outputs of forecasting, not part of the raw action definition. This prevents an artifact from already containing the forecast that it is supposed to generate.

• Raw action Source artifact, target components, interpretation boundary, candidate updates, action boundary, and observable boundary.
• Force descriptor Action class, target regions, candidate support families, affected policy or governance components, and uncertainty boundary.
• Observed effect Transition, before / after signatures, comparable deltas, unexpected witnesses, and review / CI / runtime outcome.

Operation support and policy

SFT asks which operations are lawful, but also which operations appear natural, possible, low cost, or likely to be selected in a field.

• OperationSupport The admissible operation set after constraints and governance interventions.
• OperationPolicy A preorder, cost, selection relation, or explicitly probabilistic distribution on supported operations.
• Attractor engineering Support and policy shaping, not a hidden physical force or automatic stability theorem.

ForecastCone and ConsequenceEnvelope

`ForecastCone` is the formal set of reachable field paths from a starting field, support relation, and horizon. For set-valued artifact actions, SFT forms a family of cones and summarizes them for practice as a `ConsequenceEnvelope`.

ConsequenceEnvelope
  = selected ForecastCones
  + reachable path classes
  + affected architecture regions
  + comparable signature axes
  + obstruction witness candidates
  + missing invariants / boundaries
  + forecast boundary
  + unknown / unmodeled remainder

u in alpha_a(F)
F_u := applyUpdate(F, u)
U_u := U(F_u)

ForecastConeFamilyAfterAction(F, a, h)
  = { ForecastCone(F_u, U_u, h) | u in alpha_a(F) }

Observation, governance, and FieldUpdate

Review, CI, type checking, architecture rules, AI policy, and runtime guards are governance interventions because they can change support, policy, observation, and feedback update.

`FieldUpdate` records the difference between forecast and observation: signature delta, unexpected witnesses, review or CI outcome, runtime feedback, missing evidence, and non-conclusions.

• Restrictive intervention Removes unsafe support from later accepted operations.
• Redirective intervention Raises shortcut cost and lowers lawful path cost inside the selected field model.
• Instrumenting intervention Adds observation axes, tests, runtime checks, or evidence records.
• Learning intervention Preserves observed outcomes and forecast error in posterior field memory.

Core boundary and non-conclusions

Part III defines the theorem-bearing fragment, not the whole social reality of a development organization. `ForecastCone` is a reachable path set under selected support and horizon; `ConsequenceEnvelope` is the reader-facing report that explains the cone family, unknown remainder, and forecast boundary.

The core does not assert that artifacts have unique effects, that policy is probabilistic unless a distribution is supplied, or that a field update automatically improves later forecast quality.