Rule Engine

If samples are too easy the model has nothing to learn; if they are too difficult, noisy learning signals may interfere with training; the most effective learning occurs in the region slightly above current capability but still within reach.

Fine-tuning is suitable for teaching a model a specific output style or domain tone, while RAG achieves immediate-update-ready results through an external knowledge base, and the two are often used in combination in engineering.

A rules engine is a class of software component that extracts business rules from application code, expresses them declaratively and executes them centrally.

In some scenarios a rules engine or traditional software suffices, and forcing in AI models actually increases cost and uncertainty.

In hybrid systems, when the model acts as a fact generator, the credibility of its output needs to be verified by the rule engine; otherwise untraceable errors are introduced.

Rule engines naturally provide rule-based proof paths (such as derivation trees), whereas the internal reasoning process of language models is usually opaque.

The article, in the form of an object-oriented design pattern catalog, defines 13 patterns for coupling language models with executable rule languages.

Rule engines monitor based on predefined condition-action pairs, offering strong determinism and low latency, but they struggle to enumerate the combinatorially explosive behavior space of AI agents.

In practice, heuristic algorithms or rule engines are often used to approximate a solution.

Traditional rule engines excel at handling deterministic logic (such as triggering an alarm when temperature exceeds a threshold), but are often powerless against fuzzy associations (such as material moisture affecting flowability and causing insufficient filling).

Common rule engines in engineering (such as Drools, JSON Logic) and policy languages (such as OPA/Rego) all take predicates as their core building block: each rule is a conditional expression, and a match triggers an action.

A common implementation practice is to use a rules engine for core business processes and apply model-generated agents to peripheral, low-risk repetitive tasks.

The initial failure was because the rule "another app is in the foreground, bring the display interface back" triggered before the model was consulted, causing the agent to wrongly interfere with the user's operation, with a success rate of 0/20.

The chess game built into Sidekick uses a rules engine to reject illegal moves; in the demo the system prompted "kingside castling is not legal in this position".

In board games, the rules engine's output is deterministic, reproducible and testable, and does not drift with changes in prompts or model versions.

Rules suit scenarios with clear boundaries and little change; retrieval suits scenarios that need to cite private knowledge and require traceability; pure generation suits open-ended tasks with high fault tolerance.

A rule engine refers to handling deterministic tasks with preset if-else logic or regular expressions, with the advantages of speed, low cost, and predictable results.

In telecom anti-fraud, pure rules are easily bypassed and pure models are weak on cold start and interpretability, so a common approach is for rules to handle high-certainty hard blocks and models to discover new patterns that rules cannot cover.

Traditional automation solutions usually rely on rule engines or simple keyword matching and struggle to understand context and semantic relationships; for example, they cannot distinguish the semantic difference between "temperature slightly above the setpoint but lasting very briefly" and "temperature persistently exceeding the limit".

If a simple rule, filter, better form, or conventional algorithm can solve the problem, a large language model should not be used, because LLMs bill per message and always bill, whereas rules cost nothing to run.