Stochastic local search
Algorithms AIMech:StochasticLocalSearch DRAFT
A configurable family of combinatorial search algorithms that initializes a search position and any memory, then applies a specified neighborhood transition rule until a stopping criterion holds; randomized choices are permitted, with deterministic choices included as degenerate cases.
Identity Notes & Concept Scope
This record selects the source-defined combinatorial neighborhood-search family, including configured memory and deterministic degenerate choices. Strict hill climbing, ILS/VNS/GLS/Tabu/annealing controllers and SAT-specific methods remain distinct narrower procedures. The historical ILS pointer is discovery context and does not equate every embedded optimizer with this family. Prior HillClimbing progress is preserved under owner270; continuous/terminological and full GLSM residuals remain. Fresh collection on 15 October 2026 at14:35:54–14:37:34 UTC at actual merged base 73729051e58d582f36c9af9296a92b393be0a679 compared all763 native and442 pinned AIO records (4,807 identity-field occurrences,3,674 normalized values), with zero candidate collisions and15 context-only fields across eight neighboring records. Four ignored- and hidden-inclusive checkout searches retained3,967/3,981/9,015/10,567 occurrences (27,530 total), grouped into1,338 exact matching contents. Root read all39 focused candidate-bearing decoded contexts, all15 normalized contextual fields/eight definitions, all20 full matching frontier objects and the three newly merged342 definitions. This is bounded semantic inspection; root does not claim a verbatim reading of all1,084 broader decoded contexts or every repeated occurrence. All909main and393nested objects were queried recursively; historic primary/AIO and supporting inspections retain their separately documented scopes.
Claims & Grounded Evidence
6 Claims
Mechanism
#neighborhood-search-framework
The selected combinatorial framework specifies a search space, a solution set, a neighborhood relation, initialization, and a step rule. In the authors’ later explicit exposition, the framework also specifies memory and a termination predicate: initialization selects a position and memory state, and each step selects a neighboring position and updated memory according to the specified rule.
Scope
#randomized-and-deterministic-decisions
Initialization and search steps may use randomized decisions. The framework also includes deterministic local-search procedures by representing deterministic choices as degenerate probability distributions; it does not require uniform sampling or a random decision at every step.
Mechanism
#guidance-memory-and-nonimproving-moves
An evaluation function may guide search, but it need not equal the optimization objective and may change during a run. Memory may influence the next step. Strict improvement of the current candidate is not a requirement of the family: the exposition includes methods that accept worsening moves, while treating iterative improvement as a narrower procedure.
Scope
#constructive-perturbative-and-population-positions
Search positions can encode complete candidate solutions, partial constructions, or sets of candidates. This permits perturbative, constructive and population-based procedures within the same formal framework: extending a partial solution or updating an encoded population can constitute a neighborhood step. These representations do not make the distinct procedures exact aliases.
Mechanism
#termination-and-best-encountered-solution
A run initializes its search state and applies the step rule until the supplied termination criterion holds. Under the exposition’s optimization convention, it retains the best feasible solution encountered for return, when such a solution has been encountered. For decision problems, it typically stops upon finding a feasible solution or satisfying another stopping criterion. These conventions specify bookkeeping and termination behavior rather than certify global success.
Scope
#family-and-search-control-boundary
The neighborhood-search family includes simple procedures as well as methods controlled by higher-level strategies. It is not an exact synonym of metaheuristic: the exposition distinguishes simple SLS procedures from high-level guidance and notes that some metaheuristics also use systematic search. The thesis separately introduces generalized local search machines as a way to organize search strategies and their control, rather than making that control representation the definition of every SLS procedure.
⚠️ Curated Limitations & Negative Results
- This record selects the named combinatorial neighborhood-search framework in the inspected thesis and chapter. The bare term local search is often used more narrowly for perturbative search, and its use as the name of an arbitrary embedded optimization routine does not establish the same identity. Continuous-search conventions and the full generalized-local-search-machine model are outside this scoped definition.
- This is a configurable algorithm family, not a complete executable instance. A concrete procedure must specify its representation, neighborhood, initialization, step and memory rules, evaluation, stopping, tie handling and feasibility conventions. If no feasible solution has been encountered, a best-feasible-solution return is unavailable unless an additional failure or fallback convention is supplied.
- Current search positions can worsen or recur. Keeping the best encountered value of a fixed, consistently evaluated objective makes that recorded incumbent value non-worsening when an incumbent exists; it does not make every search step improving or prove global optimality. A changing guidance function need not have the same monotonicity.
- Randomization alone does not guarantee reachability of a solution, irreducibility, finite termination, probabilistic completeness or an approximation guarantee. Such conclusions require additional assumptions on the problem, neighborhood, transition probabilities, initialization and stopping rule. A run stopped by a resource budget can return without finding a feasible or optimal solution.
- The current search position alone need not be a Markov state when the procedure uses memory or time-dependent rules. An adequate state description may include memory and a clock; this representation does not by itself imply stationarity, detailed balance or sampling from a specified target distribution.
- Allowing partial solutions and population-valued positions is a formal inclusion, not an assertion that constructive search, evolutionary algorithms, ant-colony methods, strict hill climbing and their particular controllers are identical. The family boundary also differs from the looser term metaheuristic; individual mechanisms and named compositions retain separate identities.
- The 1998 dissertation supplies the underlying search-space, neighborhood and search-control distinctions; the 2015 author-hosted overview supplies explicit memory, stopping and representation exposition without establishing invention priority. Evidence assessment is limited to the inspected defining passages and selected visuals, not the full dissertation, an unread book definition, all GLSM proofs, author software or benchmark reproduction. No universal performance ranking follows from the framework.
Artificial Intelligence Ontology (AIO) Grounding
Explicit AIO Snapshot Assessment: No Match
Rationale: The inspected AIO candidates do not adequately identify this generic combinatorial neighborhood-search family. Model-training and learning-task classes require a scope that is not mandatory here. A possible augmented-state Markov representation or use of mathematical functions is too generic to distinguish the whole algorithm family. No positive mapping is forced.
Search Scope: The fresh merged-base collection compared442 pinned AIO identities and763 native identities with ignored- and hidden-inclusive searches of four checkouts and recursive matching across909main and393nested frontier objects. Root assessed39 focused candidate contexts,15 normalized context fields and20 full matching frontier objects; broader text matches are not all claimed as root-read. Historical exact inspection of eight pinned AIO CLASS nodes and44incident edges remains applicable because the snapshot bytes are unchanged (commit397851c547d1c4d8f06ef184f63c1d40bc86937a); all eight rejection rationales are preserved. This is bounded snapshot absence, not worldwide coverage or saturation.
| Examined AIO Candidate | Rejection Reason |
|---|---|
AIO:TrainingStrategy
|
The target denotes preprocessing/training of machine-learning models. Generic combinatorial neighborhood search need not train a model. |
AIO:MachineLearningTask
|
The target is a process for building methods that learn from data; this search framework also solves fixed combinatorial instances without learning from data. |
AIO:ReinforcementLearning
|
Exploration and feedback terminology alone does not make all SLS a reinforcement-learning task; no action-value, policy or environmental-response learning rule is mandatory. |
AIO:UnsupervisedLearning
|
The framework need not learn patterns from unlabeled observations; optimizing a fixed constraint/objective is insufficient. |
AIO:EvolutionaryLLM
|
The related synonym evolutionary algorithms is attached to an LLM class. Population-valued SLS encodings do not require a language model. |
AIO:ReasoningLLM
|
SAT and constraint applications do not require an LLM or language-task reasoning architecture. |
AIO:MarkovChain
|
An appropriately augmented search state may have Markov transition semantics, but the pinned node is exported as a stochastic network/model with a probabilistic hidden-layer part. That representation alone is too generic to map the algorithm family; memoryless current-position behavior is not mandatory. |
AIO:MathematicalFunction
|
Problem-specific evaluation and transition functions are ingredients, not a distinctive mathematical function defining this entire algorithm family. |
Evidence Sources & Primary Literature
2 Sources| Source ID | Publication / Document | Type / Access | Reference & Checksum |
|---|---|---|---|
hoos1998
|
Holger H. Hoos
|
author technical report
full_text
|
sha256:a338da187d33…
|
hoos-stutzle2015
|
Holger H. Hoos, Thomas Stützle
|
author technical report
full_text
|
ID: https://doi.org/10.1007/978-3-662-43505-2_54
sha256:2203b7888ea1…
|
Curation Provenance
Curator: Codex
Method: ai_assisted
Model: GPT-6
Created: 2026-10-15T14:45:47Z
Updated: 2026-10-15T14:45:47Z
Source File:
data/curated/StochasticLocalSearch.yaml