# Tkersey Dotfiles Dotfiles > Simplify and Refactor Code Isomorphically - Skill: `tomevault-io/tkersey-dotfiles-dotfiles` (Agent Skill, multi-file: 2 files) - Install (CLI): `npx skillmds@latest add tomevault-io/tkersey-dotfiles-dotfiles` - Raw SKILL.md: https://api.skillmd.com/api/skills/tomevault-io/tkersey-dotfiles-dotfiles/raw - Safety review: pending (external: skill-scanner PASS, skillspector PASS) - Works with: Claude Code, Claude.ai, OpenAI Codex - Category: Coding & Dev Tools - Author: tomevault-io (https://skillmd.com/u/tomevault-io) - Updated: 2026-09-17 - Page: https://skillmd.com/skills/tomevault-io/tkersey-dotfiles-dotfiles --- # Simplify and Refactor Code Isomorphically ## Mission Shrink and unify code under an explicit preservation relation. ```text FACTORING -> QUOTIENTING -> ABLATIVE -> NORMALIZING ``` The reduction operators decide what disappears. The preservation relation decides what must remain. ## Preservation relations Choose before editing: - `isomorphic`: reversible structure-preserving correspondence. - `observationally-equivalent`: all declared external observations remain equal. - `refinement-preserving`: all required behavior remains while invalid, obsolete, duplicated, or unrequired behavior may disappear. - `intentional-contract-change`: approved behavior change. Default this skill to `observationally-equivalent`. Use `isomorphic` only when reversible structure matters. If the goal intentionally contracts behavior, route to `reduce` or `resolve`. ## One rule ```text Select the reduction candidate. Declare the preservation relation. Prove it. Then remove surface. ``` No proof -> no reduction. ## Mandatory loop ```text 1. BASELINE -> tests, typecheck/lints, representative observations, surface snapshot 2. FACTOR -> obligations, owners, callsites, state/effect factors 3. CLASSIFY -> clone type, live obligation, dominance, risk 4. QUOTIENT -> equivalence relation and congruence checks 5. PROVE -> preservation card before editing 6. ABLATE -> one certified lever per patch group 7. NORMALIZE -> canonical owner/representation/path 8. VERIFY -> declared observations, tests, types, lints, surface delta 9. RECOMPOSE -> prove every live obligation remains covered 10. LEDGER -> RC-v1 and rejection log 11. REPEAT -> rescan only if new candidates appear ``` Each phase must leave an artifact. A “cleaner” claim without evidence is not a simplification result. ## Preflight Before editing: - baseline relevant tests; - capture representative outputs/observations; - snapshot types/lints and surface; - map callsites and owners; - choose one reduction lever; - state rollback; - state the preservation relation. Do not require bit-identical output when the declared contract is weaker. Do not claim equivalence outside the declared observation set. ## Duplication classification Use exactly one: - `exact-clone` - `parametric-clone` - `gapped-clone` - `semantic-clone` - `accidental-rhyme` Rules: - Exact and parametric clones are quotient candidates. - Gapped clones require bounded variance and congruence checks. - Semantic clones require explicit observational equivalence proof. - Accidental rhymes must not be merged. ## Abstraction ladder ```text 0 copy-paste 1 local function 2 parameterized function 3 enum/strategy over bounded variance 4 interface/trait for open implementors 5 generic abstraction 6 DSL/macro ``` Do not skip rungs. One case is unique; two may be coincidence; three may be a pattern. One axis of variance per rung. If variance exceeds shape, keep the factors separate. ## Candidate score ```text Reduction Score = (semantic_surface_removed × confidence × ownership_clarity) / risk ``` Do not chase reductions whose coupling or proof cost exceeds the removed surface. ## Preservation Card ```yaml preservation_card: candidate_id: "..." reduction_operator: factor | quotient | ablate | normalize preservation_relation: isomorphic | observationally-equivalent inputs_and_callsites: [] observation_set: [] ordering_preserved: tie_breaking_preserved: error_semantics_preserved: laziness_and_short_circuit_preserved: floating_point_rng_hash_order_preserved: side_effect_order_and_payload_preserved: type_narrowing_preserved: UI_rerender_or_lifecycle_preserved: quotient_congruence_checks: [] proof_commands: [] status: pass | validate-first | fail | blocked ``` For non-applicable axes, say `not-applicable`; do not silently omit material axes. ## Reduction Certificate Every implemented patch group emits `RC-v1` from [reduction-certificate.md](references/reduction-certificate.md). Required: - every factor has a live obligation or removal disposition; - every retained distinction has a witness; - quotient classes are congruent; - every removed factor is accounted for; - recomposition covers every live obligation; - no orphan surface remains. ## Common candidates - pass-through wrappers and adapters; - orphan `_v2`, `_new`, `_old`, or `_improved` surfaces; - dead flags, imports, mocks, exports, and compatibility paths; - duplicate truth owners; - repeated branch structure; - wrapper chains and re-export webs; - boilerplate whose replacement has matching semantics; - abstraction rungs that exceeded evidence. ## One lever per patch group Examples: ```text delete dead branch collapse wrapper chain quotient duplicate state variants canonicalize one owner retire flag replace repeated boilerplate ``` Do not combine unrelated reductions unless they are one factorization/recomposition move. ## Verification Run: - declared observation checks; - relevant tests; - typecheck/lints; - surface delta; - recomposition audit. A green test suite alone does not prove isomorphism or observational equivalence. ## Handoff boundary Route to: - `complexity-mitigator` for read-only local comprehension; - `reduce` for broad architectural winnowing or refinement-preserving contraction; - `review-compression-compiler` / `resolve` for behavioral quotienting driven by review observations; - `fixed-point-driver` to realize an already-certified normal form; - `universalist` when reduction reveals missing essential structure. ## Output End with: ```text Reduction Bottom Line: - factors: - quotient: - ablation: - normal form: - preservation relation: - proof: - recomposition: - surface delta: - next: ``` ## Resources - [reduction-certificate.md](references/reduction-certificate.md) --- > Source: [tkersey/dotfiles](https://github.com/tkersey/dotfiles) — distributed by [TomeVault](https://tomevault.io).