Padding to a given level, and the product of two presentations #
Two constructions the answer-reduced sampler needs (sec:ar-verifier, ld_compiler.tex): its
CL functions are the direct sums of the oracularized sampler's, with ℓ levels, and the
downsized PCP sampler's, with three, on disjoint registers, at the common level max ℓ 3.
CLFun.liftTo T L h PpadsPwith trivial levels to exactlyL ≥ ℓlevels (liftNpads by a number of levels, andℓ + (L - ℓ)is notLby definition, so the level is cast alongcastLevel). Evaluation and exactness are unchanged (eval_liftTo,ExactlyOn.liftTo).CLFun.prod P Qis the presentation onι ⊕ κrunningPon the left coordinates andQon the right: the paper's direct sum onV₁ ⊕ V₂, asdirectSumof the two embeddings. It is exact on everything when both are (ExactlyOn.prod), and evaluates componentwise (eval_prod).
Casting and padding the level #
A presentation with a levels as one with b = a levels.
Equations
- MIPRE.CL.CLFun.castLevel h P = h ▸ P
Instances For
Pad to exactly L levels, the extra levels trivial on V_T.
Equations
- MIPRE.CL.CLFun.liftTo T L h P = MIPRE.CL.CLFun.castLevel ⋯ (MIPRE.CL.CLFun.liftN T (L - ℓ) P)
Instances For
The product of two presentations #
The product: P on the left coordinates, Q on the right.
Equations
Instances For
The queries of a direct sum #
A sampler answers marginal, linear-map and factor queries (truncate, mapOfPrefix,
factorOfPrefix). For a direct sum of presentations on disjoint register subspaces each query is
answered componentwise; for a padded presentation, as for the unpadded one.
A presentation on V_T reads its prefix only on T.
A presentation on V_T reads its prefix only on T.