Lookup Table (LUT) arguments are a central efficiency primitive in modern SNARKs, and existing high-performance constructions are largely tailored to large fields. Meanwhile, an increasingly important class of applications is natively ring-based, with arithmetic carried out over residue rings . We find that naively extending field-based lookup table techniques to rings faces fundamental obstacles, which can lead to unsoundness, limited applicability, or poor efficiency.
We introduce , a general framework for constructing LUT arguments over arbitrary residue ring that supports arbitrary tables. Our main technical tool is a new primitive called Cross-Modulus Consistency (CMC) PIOP, proves that two witnesses defined over coprime moduli share the same underlying integer in the canonical range. Using our CMC PIOP as a glue, we perform the lookups over an auxiliary field (for a prime ) and then certify the consistency between the witness over and the witness over , thereby avoiding the obstacles of constructing LUT arguments directly over rings. We further provide two optimized instantiations, - for and - for , capturing common modulus families in practice. Finally, we implement - and - as stand-alone PIOPs and report prototype results that corroborate our theoretical efficiency.