Multivariate Lookup Arguments

\gdef\delim#1#2#3{\mathopen{}\mathclose{\left#1 #2 \right#3}} \gdef\p#1{\delim({#1})} \gdef\ps#1{\delim\{{#1}\}} \gdef\F{\mathbb F} \gdef\vec#1{\mathbf{#1}} \gdef\eq{\operatorname{eq}}

Most lookup protocols are based on univariate polynomials. In the multivariate sumcheck setting can use different techniques from the Lasso line of work.

Lookup arguments and indexed lookup arguments.

Grand Products

A grand product reduces a claim of the form a = \prod_{\vec x} p(\vec x) to a claim of the form p(\vec r) = h for some \vec r, h.

Tha13 Proposition 2 proposes a GKR-like protocol specialized for the grand product case.

p_{i+1}(z) = \sum_{p \in \ps{0,1}^{n_i}} \eq (z,p) \cdot p_i(p, 0) \cdot p_i(p, 1)

SL20 Lemma 5.1

To prove

p = \prod_{x \in \ps{0,1}^n} v(x)

g(\vec z) = \sum_{\vec x \in \ps{0,1}^n} \eq (\vec z, \vec x) ⋅ \p{ f(1, \vec x) - f(\vec x, 0) ⋅ f(\vec x, 1) }

  1. g(\vec r_0) = 0
  2. f(0, \vec r_1) = v(\vec r_1)
  3. f(\vec 1, 0) = p

Batching of grand products.

STW23 appendix E.

Multiset Equality

Offline Memory Checking

Spark / Surge

Lasso

LogUp-GKR

Generalized Lasso

References

Remco Bloemen
Math & Engineering
https://2π.com