--- title: "Neurosymbolic AI vs LLMs" canonical: "https://xerj.org/science/neurosymbolic-ai" updated: "2026-11-14" source: "content/science/neurosymbolic-ai.md" --- # Neurosymbolic AI vs LLMs **Short answer** (updated 2026-11-14): What is neurosymbolic AI vs an LLM? A language model alone proposes an answer in its own text. A neurosymbolic system also runs a program or a formula and checks the result against facts. XERJ Query-1 is one: it compiles a prompt to a verifiable search program, then checks the answer against stored facts. **TL;DR** A language model alone proposes an answer in its own text. Neurosymbolic AI also runs a program or a formula and checks the result against facts. XERJ Query-1 is one: it compiles a prompt to a verifiable search program. ## Agent prompt ```text Act as a coding agent. Read https://xerj.org/llms.txt, install XERJ, start a local node, index one folder I point you to, and run one search so I can see a cited passage. ``` *Figure: The split follows how XERJ describes Query-1 and Reader-1, and the published Model.Surgery line: models that propose, programs you can read, and facts that check the answer. No new benchmark is claimed here.* ## How they differ A language model is strong at reading a question or a document and proposing a next step. It is a poor place to hide the final number, because you cannot rerun a hidden step. A neurosymbolic system still uses that neural strength. It also has a symbolic engine that runs a short program, or a formula, over stored facts or over words on a page. You can read the program, and you can run it again. The comparison is not neural versus not neural. It is proposal only versus proposal, then a check. ## How XERJ uses it XERJ Query-1 is a neurosymbolic model that compiles a prompt to a verifiable search program, then checks the result against facts. It ships in rc.101. The product page is [XERJ Query-1](/xerj-query-1). The write-up is the [Query-1 post](/blog/xerj-query-ai-model). XERJ Reader-1 writes a formula over a document, and the value is calculated from the words on the page. If the documents do not support an answer, it replies Not Found. See [grounded answers](/science/grounded-answers). On 12 November 2026, Model.Surgery joined XERJ to build neurosymbolic systems. The published line from that post is: models that propose, programs you can read, and facts that check the answer. The closer look at running a program on symbols is [symbolic execution for LLMs](/science/symbolic-execution). The general concept page is [What are neurosymbolic models?](/science/neurosymbolic-models). ## History and research A recent survey is d'Avila Garcez and Lamb, [Neurosymbolic AI: The 3rd Wave](https://arxiv.org/abs/2012.05876) (arXiv 2020, later in Artificial Intelligence Review 56, 2023). That paper is a survey of the field. It is not a description of Query-1 or Reader-1. XERJ's product wording is the source for how the idea appears in this product. ## Guides Read how XERJ builds it: [Model.Surgery joins XERJ](/blog/model-surgery-joins-xerj), [XERJ Query-1](/blog/xerj-query-ai-model) and [XERJ Reader-1](/blog/xerj-reader-1-waitlist). ## Related terms [Neurosymbolic models](/science/neurosymbolic-models), [symbolic execution](/science/symbolic-execution), and [grounded answers](/science/grounded-answers). ## FAQ ### What is neurosymbolic AI? It is a system that pairs a neural model, which proposes, with a symbolic engine, which runs a program or formula and checks it against facts or against words on a page. ### How is this different from an LLM alone? A language model can draft a program or a reply. In a neurosymbolic system the symbolic part runs that program and checks the result, so the final number is not hidden in the model. ### How does XERJ Query-1 use this? Query-1 compiles a prompt to a verifiable search program over stored facts, and ships in rc.101. Reader-1 writes a formula over a document. If the evidence is missing, the answer can be Not Found. ### Where is the broader concept page? The concept page for the models themselves is What are neurosymbolic models? This page is the comparison with a language model alone. ## Related - [What are neurosymbolic models?](/science/neurosymbolic-models) - [Symbolic execution for LLMs](/science/symbolic-execution) - [What are grounded answers?](/science/grounded-answers) - [XERJ Query-1](/xerj-query-1) - [XERJ Query-1](/blog/xerj-query-ai-model) - [Model.Surgery joins XERJ](/blog/model-surgery-joins-xerj) - [XERJ Reader-1](/blog/xerj-reader-1-waitlist) - [BM25 vs vector search](/science/bm25) (same intent: Science) - [Hybrid vs vector vs semantic search](/science/hybrid-vs-vector-vs-semantic-search) (same intent: Science) - [What is agentic memory?](/science/agentic-memory) (same intent: Science)