100 Reasoning Methods

I. Classical Logical Reasoning (Deductive)

  1. Modus Ponens
    Description: If A → B and A is true, then B follows.
    Applications: Formal logic systems, theorem proving, expert systems.
  2. Modus Tollens
    Description: If A → B and ¬B, then infer ¬A.
    Applications: Automated reasoning, error detection, rule-based AI.
  3. Syllogistic Reasoning
    Description: Deductive reasoning using categorical premises, e.g., all A are B, C is A → C is B.
    Applications: Legal reasoning, semantic reasoning in NLP.
  4. Propositional Logic
    Description: Logic involving truth-functional operators (¬, ∧, ∨, →, ↔).
    Applications: Digital circuit design, logic programming.
  5. Predicate Logic (First-order logic)
    Description: Extends propositional logic with quantifiers and predicates.
    Applications: Knowledge representation, semantic web, theorem proving.
  6. Higher-order Logic
    Description: Quantifies over predicates or functions, not just individuals.
    Applications: Formal mathematics, type theory, advanced proof systems.
  7. Modal Logic
    Description: Handles necessity and possibility using modal operators.
    Applications: AI planning, verification, belief modeling.
  8. Temporal Logic
    Description: Adds time modalities (always, eventually, etc.) to logic.
    Applications: Formal verification, real-time systems, temporal databases.
  9. Deontic Logic
    Description: Formalizes obligations, permissions, and prohibitions.
    Applications: Ethical AI, law modeling, policy checking.
  10. Automated Theorem Proving
    Description: Algorithms that prove mathematical/logical statements using formal systems.
    Applications: Formal methods, logic engines, mathematics.

II. Probabilistic Reasoning

  1. Bayesian Inference
    Description: Updates beliefs based on new evidence using Bayes’ theorem.
    Applications: Diagnostics, spam filters, medical AI.
  2. Bayesian Networks
    Description: Graphical models representing probabilistic dependencies among variables.
    Applications: Causal reasoning, decision support, risk analysis.
  3. Hidden Markov Models (HMMs)
    Description: Probabilistic models with hidden states and observable outputs.
    Applications: Speech recognition, bioinformatics, time-series analysis.
  4. Markov Networks
    Description: Undirected probabilistic graphical models capturing joint distributions.
    Applications: Image processing, contextual reasoning.
  5. Monte Carlo Inference
    Description: Uses random sampling to approximate probabilistic inference.
    Applications: Uncertainty modeling, physics simulations.
  6. Variational Inference
    Description: Approximates intractable distributions via optimization.
    Applications: Bayesian deep learning, topic modeling.
  7. Probabilistic Programming
    Description: Incorporates random variables into programming languages for model definition.
    Applications: Probabilistic simulations, automated model building.
  8. Bayesian Occam’s Razor
    Description: Penalizes models with more assumptions unless strongly supported by data.
    Applications: Model selection, scientific discovery.

III. Defeasible and Non-monotonic Reasoning

  1. Defeasible Logic
    Description: Reasoning that allows conclusions to be retracted in light of new evidence.
    Applications: Legal AI, commonsense reasoning.
  2. Default Logic
    Description: Allows use of defaults in the absence of conflicting information.
    Applications: Legal reasoning, expert systems.
  3. Circumscription
    Description: Prefers minimal models consistent with known information.
    Applications: Commonsense AI, non-monotonic knowledge bases.
  4. Belief Revision (AGM Theory)
    Description: Framework for changing beliefs systematically when new information contradicts old.
    Applications: Knowledge bases, epistemic logic.
  5. Answer Set Programming (ASP)
    Description: Logic programming paradigm for solving combinatorial problems with stable models.
    Applications: Planning, scheduling, knowledge representation.

IV. Abductive Reasoning

  1. Abductive Logic Programming
    Description: Infers the best explanation for observations.
    Applications: Fault diagnosis, natural language understanding.
  2. Explanation-Based Learning (EBL)
    Description: Uses generalizations of explanations from specific examples to learn.
    Applications: Machine learning, XAI.
  3. Hypothesis Ranking
    Description: Orders possible explanations by likelihood or simplicity.
    Applications: Scientific modeling, AI explainability.
  4. Minimal Explanation Principle
    Description: Prefers explanations that account for observations with fewest assumptions.
    Applications: Cognitive science, automated discovery.

V. Analogical Reasoning

  1. Structure-Mapping Theory
    Description: Infers analogies based on matching relational structure, not just surface similarity.
    Applications: Educational AI, analogy-based problem solving.
  2. Case-Based Reasoning (CBR)
    Description: Solves new problems by adapting past solutions to similar situations.
    Applications: Legal AI, diagnostics.
  3. Analogy by Embedding Similarity
    Description: Uses high-dimensional vector similarity to model analogical closeness.
    Applications: NLP, recommendation systems.

VI. Causal Reasoning

  1. Structural Causal Models (SCMs)
    Description: Graphical models with directed edges representing causal relationships.
    Applications: Epidemiology, economics, policy analysis.
  2. Interventional Reasoning (do-calculus)
    Description: Computes the effect of external interventions on a system.
    Applications: Causal inference, experiment design.
  3. Counterfactual Reasoning
    Description: Explores “what if” scenarios by modifying past events in models.
    Applications: Law, ethics, causal analysis.
  4. Causal Discovery Algorithms
    Description: Learns causal structure from observational or interventional data.
    Applications: Scientific discovery, fairness in AI.

VII. Commonsense and Intuitive Reasoning

  1. Script-Based Reasoning
    Description: Uses stereotyped sequences of events (scripts) for inference.
    Applications: Narrative understanding, dialogue systems.
  2. ConceptNet-Based Reasoning
    Description: Uses large-scale commonsense knowledge graphs for inference.
    Applications: Chatbots, context-aware systems.
  3. Prototype-Based Reasoning
    Description: Uses typical examples rather than formal definitions to make inferences.
    Applications: Categorization, informal reasoning.
  4. Heuristic Reasoning
    Description: Uses simplified strategies or rules of thumb.
    Applications: Decision-making under time constraints.
  5. Fast and Frugal Trees
    Description: Decision trees with minimal depth for quick judgments.
    Applications: Emergency decision-making, cognitive modeling.

VIII. Symbolic and Knowledge-Based Reasoning

  1. Ontology-Based Reasoning
    Description: Uses formal representations of concepts and their relations.
    Applications: Semantic web, knowledge graphs.
  2. Semantic Reasoning Engines
    Description: Deduce new knowledge from structured vocabularies and taxonomies.
    Applications: Medical informatics, information integration.
  3. Production Rules
    Description: If-then rules representing knowledge.
    Applications: Expert systems, planning.

IX. Neural and Deep Learning-Based Reasoning

  1. Transformer Attention Mechanisms
    Description: Learns dependencies across input positions for reasoning.
    Applications: LLMs, vision transformers.
  2. Chain-of-Thought (CoT) Prompting
    Description: Guides LLMs to reason step-by-step before final answers.
    Applications: Math word problems, logic puzzles.
  3. Tree-of-Thoughts (ToT)
    Description: Explores reasoning paths as a tree structure with evaluation.
    Applications: Planning, multi-step reasoning.
  4. Graph-of-Thoughts
    Description: Generalizes ToT with non-linear reasoning graphs.
    Applications: Complex problem-solving, agent systems.
  5. Self-Consistency Decoding
    Description: Samples multiple reasoning paths and selects the most consistent answer.
    Applications: Robust question answering.
  6. Meta-CoT
    Description: Uses a second-level reasoning model to supervise CoT.
    Applications: Meta-reasoning, verification.
  7. Self-Ask Prompting
    Description: Prompts the model to ask and answer sub-questions.
    Applications: Multi-hop QA.
  8. ReAct (Reason + Act)
    Description: Combines reasoning traces with real-time tool use.
    Applications: Agent systems, web automation.

IX. Neural and Deep Learning-Based Reasoning

  1. Auto-CoT Prompting
    Description: Automatically generates chain-of-thought examples from questions for model fine-tuning.
    Applications: LLM training, zero-shot reasoning improvement.
  2. LogiCoT (Logical Chain-of-Thought)
    Description: Incorporates formal logical constraints into chain-of-thought reasoning.
    Applications: Symbol-sensitive reasoning, verifiable logic inference.
  3. Toolformer Agents
    Description: AI models that learn when and how to use external tools during reasoning.
    Applications: API-driven agents, dynamic workflows.
  4. Retrieval-Augmented Reasoning (RAG)
    Description: Uses external documents or knowledge bases to support reasoning.
    Applications: Question answering, research assistants.
  5. In-Context Learning with Demonstrations
    Description: LLMs learn reasoning patterns by observing few-shot examples within a prompt.
    Applications: Classification, decision-making under minimal supervision.
  6. Graph Neural Reasoning
    Description: Learns over graph structures, capturing entity and relationship semantics.
    Applications: Molecule modeling, social network reasoning.
  7. Latent Space Reasoning
    Description: Logical operations or inference performed in a continuous latent embedding space.
    Applications: Language modeling, symbolic regression.
  8. Contrastive Reasoning via Embeddings
    Description: Models learn to reason by distinguishing similar from dissimilar cases.
    Applications: Retrieval, entailment tasks.
  9. Visual CoT (Multimodal Chain-of-Thought)
    Description: Combines image and text inputs for step-wise visual reasoning.
    Applications: VQA (visual question answering), robotics.
  10. Cross-modal Reasoning
    Description: Performs inference across vision, audio, language, etc., jointly.
    Applications: Multimodal assistants, embodied agents.

X. Hybrid Neuro-Symbolic Reasoning

  1. Neuro-Symbolic Concept Learner
    Description: Learns symbolic representations from raw data for structured reasoning.
    Applications: Visual understanding, interpretable AI.
  2. Logic Tensor Networks (LTNs)
    Description: Integrates logic rules with neural representations using differentiable logic.
    Applications: Scene understanding, knowledge base completion.
  3. Neural Theorem Provers
    Description: Combines learning with symbolic deduction in proof tasks.
    Applications: Mathematics, logic verification.
  4. DeepProbLog
    Description: Combines deep learning with probabilistic logic programming.
    Applications: Visual reasoning, program synthesis.
  5. Scallop (Differentiable Datalog)
    Description: Declarative probabilistic reasoning via differentiable Datalog execution.
    Applications: Interpretable program learning, knowledge-intensive NLP.
  6. Neuro-Symbolic Relational Learning
    Description: Learns relational facts and their logical rules simultaneously.
    Applications: Ontology reasoning, inductive logic programming.
  7. Symbolic AI-Augmented Planning
    Description: Combines logic-based planning with LLMs or neural predictors.
    Applications: Agent coordination, robotics.
  8. Symbolic Regression
    Description: Learns interpretable mathematical expressions that fit observed data.
    Applications: Scientific discovery, formula extraction.

XI. Decision-Theoretic and Reinforcement Reasoning

  1. Markov Decision Processes (MDPs)
    Description: Models agents acting in stochastic environments with states and rewards.
    Applications: Control systems, reinforcement learning.
  2. Partially Observable MDPs (POMDPs)
    Description: Extends MDPs to handle uncertainty in state observation.
    Applications: Autonomous navigation, medical decision-making.
  3. Deep Reinforcement Learning (DRL)
    Description: Learns policies via neural networks from interaction with environments.
    Applications: Games (e.g., Go), robotics, finance.
  4. Model-Based RL
    Description: Builds internal models of environment dynamics to plan actions.
    Applications: Sample-efficient learning, control.
  5. Policy Gradient Methods
    Description: Directly optimizes the agent’s policy via gradient descent.
    Applications: Continuous action spaces, robotics.
  6. Reward Shaping and Inverse RL
    Description: Infers reward functions from observed behaviors.
    Applications: Human imitation, ethical alignment.
  7. RLHF (Reinforcement Learning with Human Feedback)
    Description: Uses human preference data to guide learning.
    Applications: LLM fine-tuning, safe AI.
  8. DPO (Direct Preference Optimization)
    Description: Optimizes AI models directly from ranked preference data.
    Applications: Preference-based language generation.
  9. Multi-agent Game-Theoretic Reasoning
    Description: Models interactions among multiple decision-making agents.
    Applications: Economics, competitive AI agents.

XII. Meta-Reasoning and Self-Reflective Architectures

  1. Meta-CoT Reasoning
    Description: Higher-level reasoning system evaluates or corrects another’s reasoning chain.
    Applications: Self-verification, robustness.
  2. Self-Reflective Agents
    Description: AI systems that reason about their own beliefs, goals, and actions.
    Applications: Ethical agents, planning under uncertainty.
  3. Debate-Driven Reasoning (AI Debate)
    Description: Multiple models argue contrasting viewpoints to improve reliability.
    Applications: Alignment, truth-seeking.
  4. Auto-Verification Agents
    Description: Models that reason about the validity of their own outputs.
    Applications: Fact-checking, scientific research.
  5. Long Context Memory Reasoning
    Description: Uses extended memory (100K+ tokens) to maintain coherent reasoning.
    Applications: Legal document understanding, historical analysis.
  6. Reasoning with External Memory Systems
    Description: Uses databases or vector stores to store and retrieve intermediate inferences.
    Applications: Agent memory, augmented LLMs.

XIII. Cutting-Edge and Novel Reasoning Frameworks

  1. Tree of Thoughts (ToT) Search Algorithms
    Description: Multi-step exploration with pruning and selection strategies.
    Applications: Creative problem solving, planning.
  2. Graph of Thoughts
    Description: Captures reasoning paths as interconnected graphs, not linear chains.
    Applications: Scientific workflows, multi-goal agents.
  3. Function-Calling LLMs
    Description: Reason by delegating sub-problems to code or external APIs.
    Applications: Developer agents, simulation pipelines.
  4. Q-Learning with Reasoning Traces
    Description: Combines step-wise explanation with Q-value estimation.
    Applications: Transparent reinforcement learning.
  5. Multimodal Reasoning Transformers
    Description: Integrates images, audio, and text for joint inference.
    Applications: Assistive AI, VQA, robotics.
  6. Multi-Agent Planning Architectures
    Description: Distributes reasoning across agents coordinating to solve sub-tasks.
    Applications: Simulation, cooperative AI.
  7. AlphaGeometry
    Description: LLM-guided symbolic reasoning in mathematical geometry.
    Applications: Geometry solvers, STEM education.
  8. Gradient-Logic Networks
    Description: Combines gradients with symbolic logic inference.
    Applications: Explainable neural-symbolic AI.
  9. Value Learning for Moral Reasoning
    Description: Infers moral principles from behavior or instructions.
    Applications: Ethics, alignment.
  10. Sparse Attention Reasoning Models
    Description: Uses sparse context to focus reasoning on key parts of input.
    Applications: Scalable transformers, efficiency.
  11. Memory-Compressed Reasoning Transformers
    Description: Reduces context complexity while maintaining logical flow.
    Applications: Edge devices, long-context inference.
  12. Self-Improving LLMs via Reflection
    Description: AI models that adjust prompts or sampling based on self-evaluation.
    Applications: Autonomous tutors, debugging.
  13. Contrastive CoT
    Description: Generates contrasting reasoning paths to reinforce correct inference.
    Applications: Error analysis, model robustness.
  14. Recurrent LLM Architectures
    Description: Iteratively refines answers through reasoning steps.
    Applications: Long conversations, multi-stage planning.
  15. Adaptive Step Reasoning
    Description: Dynamically chooses number of reasoning steps needed.
    Applications: Efficiency in large model deployments.
  16. Debate + Voting Models
    Description: Generates multiple candidate arguments and selects via voting.
    Applications: Legal AI, opinion summarization.
  17. Planning-Driven LLM Agents
    Description: Integrates planning algorithms (like A*) with language reasoning.
    Applications: Robotics, task completion agents.