Elamur Groupantsworld-principles-list-boundary
The groupant beside world/src/principles.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 source model | forward |
| ast | partial | ../syntax.json |
| composition | partial source model | composition |
| cost | partial source model | cost |
| descriptant | partial source model | epoch-memory |
| invariant | partial source model | invariant |
| tests | partial source model | checks |
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 |
|---|---|---|---|
world-principles-list-boundary-behavior-complement | behavior_complement | partial source model | behavior-complement |
world-principles-list-boundary-reverse-reconstruction | reverse_reconstruction | partial source model | reverse-reconstruction |
world-principles-list-boundary-coupling | constraint_relation | partial source model | coupling |
Model text
forward
For requested n and candidate count L, list_step=max(1,floor(L/n)) when n>0 and 1 when n=0. CLI list takes n items from indices 0,stride,2stride,... below L. Therefore n=0 emits none; positive limits preserve the previous spacing. Other CLI branches perform round or status I/O.
invariant
Stride is nonzero for all usize inputs. The selected iterator yields at most min(L,n) rows; output does not imply all pending facts were listed. A zero request still loads pending knowledge before selection; only the division panic is repaired.
cost
Constant step calculation; O(min(L,n)) iterator observations after pending construction. No reduction of knowledge-loading cost is claimed.
composition
Source callers: main dispatches main_args; family invokes round once per research round and reports returned counts/errors; round consumes pending and statement then external teacher/cache/world operations. Native public join: caller-supplied know::Fact -> statement. Selection tests call the exact private pure helper used by pending with supplied keys, avoiding filesystem state.
epoch-memory
2026-10-30: initial source-bound review. Prospective cost model predicts no asymptotic change: selection helper extraction preserves sorting and cloning; list repair replaces one scalar division with checked division. Old zero-limit native witness divides by zero. Final implementation returns a nonzero stride and take(0) produces no rows. Mind production behavior is unchanged. No surrogate, speed or full-system correctness claim.
checks
cargo test -p world --lib principles::wave12_models -- --test-threads=1. File evidence.md binds repeated native profiles and compiled production controls. Partial syntax leaves macros opaque; source-bound syntax is not semantic AST verification.
behavior-complement
Domain and observation scope: Pure list_step(L,n) and step_by/take index observations for usize L,n; CLI loading excluded.
In U={(L,n,s,J)}, exclude s=0, s differing from max(1,floor(L/n)) for n>0, s differing from 1 for n=0, or J differing from the first n multiples of s below L. Any nonempty J for n=0 or L=0 is absent. 400 finite cases check this scalar/index relation; CLI load failures and load avoidance are not covered.
reverse-reconstruction
For (s,J), retain every (L,n) satisfying the stride equation and exact bounded-multiple prefix; J alone existentially retains compatible s. Empty J admits n=0 and/or L=0. Nonempty J's last index is below L, while truncation permits multiple larger L,n pairs. Fact values are outside the index observation.
coupling
400 finite L,n pairs compare actual step_by/take against independently constructed arithmetic indices, including twenty zero limits. Old arithmetic panics at L=n=0; checked_div repair preserves all positive n. CLI I/O remains unexecuted.
Typed entries bind the manifest source revision, this section's domain/operator/observation, and the named finite checks. Status is partial source-derived model. No complete reconstruction search, universal proof or factual-truth guarantee is claimed.
This page in Markdown → https://md.groupants.elamur.ai/free/en/mova/world/src/principles.rs.groupant/list-boundary.groupant/