# Lookups Lookup instructions require their logic to have some structure to apply the prefix-suffix sumcheck, as described in Appendix A of [Proving CPU Executions in Small Space](https://eprint.iacr.org/2025/611). That is: * The lookup table must have an MLE that is efficiently evaluable by the verifier. The `JoltLookupTable` trait encapsulates this MLE. * The lookup index can be split into a prefix and suffix, such that MLEs can be evaluated independently on the two parts and then recombined to obtain the desired lookup entry. * Every prefix/suffix MLE is efficiently evaluable (constant time) on Boolean inputs. JOLT Atlas reuses some of the instruction from the original JOLT codebase and adds new ones applying the same paradigm. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://devs.novanet.xyz/jolt-atlas-zkml/onnx/tensor-instructions/lookups.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.