world-big-sampling

The groupant beside world/src/big.rs in the Mova repository: what the code computes, what it never does, how to go back from its outputs, its invariants, cost and checks.

Facts

Implementation material. A Mova code model describes this code at one source revision: partial models, finite checks and their stated scope. It is not a reviewed general exposition, and its labels are shown as written, never raised.

Components

component	label	where
approximant	partial	approximant
ast	partial	`../syntax.json`
composition	partial	composition
cost	partial	cost
descriptant	present	descriptant
invariant	partial	invariant
tests	partial bounded parent tests	tests

Obernants

The typed relations around the forward model: the behaviour complement (what the code never does), the reverse reconstruction (every input compatible with an output) and specialised views.

id	type	label	where
`behavior_complement`	behavior_complement	partial source derived model	behavior_complement
`reverse_reconstruction`	reverse_reconstruction	partial source derived model	reverse_reconstruction
`world_big_sampling_invariants`	world_big_sampling_invariants	partial source derived model	world_big_sampling_invariants
`world_big_sampling_resource_cost`	world_big_sampling_resource_cost	partial source derived model	world_big_sampling_resource_cost
`world_big_sampling_representation_join`	world_big_sampling_representation_join	partial source derived model	world_big_sampling_representation_join
`world_big_sampling_domain_partition`	world_big_sampling_domain_partition	partial source derived model	world_big_sampling_domain_partition

Model text

descriptant

world-big-sampling

E={i | allowed(place(i).book) AND high4(wrapping_mul(i,K))=bucket}; Y=E if |E|<=n else [E[floor(k*|E|/n)]]k<n.

Modeling epoch 2026-10-31

Prospective source/branch/cost hypotheses were saved externally before source edits. This partial source-derived model retains observed boundaries rather than claiming complete verification. Only domain/group runtime test; sampling, cache and external judgment source-modeled, no executable surrogate.

approximant

Forward relation

E={i | allowed(place(i).book) AND high4(wrapping_mul(i,K))=bucket}; Y=E if |E|<=n else [E[floor(k*|E|/n)]]k<n.

Domain: Well-formed store; f64 integer conversion/huge lengths not proved.

No executable percent surrogate: these categorical/effect observations lack a useful approximation metric. Future supported caps1/2/5/10% need a defined domain/metric and real reference evidence; no error or speed bound is claimed.

invariant

Store opens before books.tsv; accepted indices ascending; no sentence-length filter here.

Cost component: cost.md.

cost

Store-wide scan and candidate allocation O(S log B+C), not O(n).

composition

Store::place book u32 joins TSV first field; parser token-length gate follows selection.

models

behavior_complement

bucket16 cannot match high4. n0 iterates no output indices even though ratio infinity may be computed. Missing/invalid metadata id/group rows excluded; repeated book id last-wins.

reverse_reconstruction

Y empty admits zero cap, no eligible indices or out-of-range bucket; nonempty Y constrains hash but not skipped text or candidate total.