Elamur Groupantsworld-lessons-eval
The groupant beside world/src/lessons.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-lessons-eval-behavior-complement | behavior_complement | partial source model | behavior-complement |
world-lessons-eval-reverse-reconstruction | reverse_reconstruction | partial source model | reverse-reconstruction |
world-lessons-eval-coupling | constraint_relation | partial source model | coupling |
Model text
forward
Tokenize ASCII identifiers and integer strings, then precedence-climb with eager operands. Comparisons/Booleans return 0 or 1. Division requires zero remainder. Checked i64 add/subtract/multiply/negation/division/remainder propagate None on overflow. Entire token stream must be consumed.
behavior-complement
U is finite expressions/environments with sufficient stack, paired with Option<i64>. Inner complement excludes Some for unknown symbols, invalid suffix, inexact or zero division and overflow. Eager evaluation excludes Some(0) for 0 && (1/0).
reverse-reconstruction
B(v) is every syntactically accepted expression and environment evaluating to v. For v=2, 1+1 and 4/2 are compatible; unused bindings remain arbitrary. B(None) mixes syntax, missing-name, inexactness and overflow failures.
coupling
Failure partition retains reasons only in the model: runtime None merges them. Literal positive 9223372036854775808 cannot be parsed, so MIN is accessible through an environment or representable computation, not that positive token followed by unary minus.
invariant
Successful observations obey the declared forward relation with the same supplied state and order. Failure is explicit; no hidden label or retained-state guarantee is introduced.
cost
Tokenization O(B); map probes O(log V); parser visits O(T) tokens, with recursive stack O(T) worst-case. Arbitrary nesting can exhaust the stack; no universal totality claim.
composition
Evaluation and substitution share numeric bindings; field labels choose template containers. Child relations must agree on intermediate state, not merely final counts. Partial syntax binds the source; macro contents are opaque.
epoch-memory
Initial review predicted arithmetic overflow and finite-pool boundary failures. Old native code failed six named witnesses: overflow, empty templates, name exhaustion, full-width range, reversed range and seed overflow. Narrow repairs retain public signatures; finite observations do not establish arbitrary-input totality. See file evidence.md for hashes and repeated results.
checks
Eight wave12_models tests plus two existing lesson tests. Independent 19 by 19 by 7 arithmetic cases, precedence/eager failure literals, partition/substitution fixtures and exactly 2000 rejected RNG draws. Runtime guard mutations must fail named assertions. Evidence is finite; no whole-world or live course claim.
This page in Markdown → https://md.groupants.elamur.ai/free/en/mova/world/src/lessons.rs.groupant/eval.groupant/