Concepts/Definition

Application context: abstraction supports transfer and can also erase decisive differences

Résumé screening and code scanning can both be abstracted as fan out, process, and gather. Back in the field, résumé work may hide sensitive attributes and require a hiring owner to adjudicate. Code work may isolate worktrees, run tests, and require a repository owner to merge. Matching arrows alone cannot guide authority, state, or acceptance.

Definition

The Abstraction–Reconstruction Loop moves in two directions. Abstraction extracts a reusable problem, forces, and structure from cases. Reconstruction places that structure back into concrete roles, objects, states, authority, evidence, failure consequences, and acceptance conditions. Failed reconstruction indicates excessive abstraction or an incomplete pattern boundary.

Engineering mechanism

Each candidate pattern is reconstructed at least twice: once in its source case to ensure that decisive details survive, and once in an independent domain to ensure that the pattern does not depend on source-specific vocabulary. Any difference that changes a business judgement, state transition, power boundary, evidential force, next action, accountability, or acceptance must remain explicit.

Boundary

The loop evaluates pattern extraction; it does not require identical implementations. A structure that can only be explained in its source project remains a case concept. A structure that reconstructs into checkable design actions in another domain can become a pattern candidate.