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argumentation-values

The argumentation-values crate (v0.1.0) implements value-based argumentation frameworks (Bench-Capon 2003) extended with multi-value support per Kaci & van der Torre (2008). It adds Value, ValueAssignment<A>, Audience, and ValueBasedFramework<A> on top of the core argumentation crate, plus subjective/objective acceptance, a Walton-scheme→audience bridge, APX format I/O for ASPARTIX interop, and MultiAudience consensus queries for multi-character scenes.

Crate: argumentation-values (crates.io · rustdoc)

Key types​

Value​

A newtype around String representing a value an argument can promote (e.g., Value::new("life")). Implements Display, From<&str>, From<String>, Hash, Ord. → Full docs

ValueAssignment<A>​

Maps each argument (of label type A) to the set of values it promotes via SmallVec<[Value; 1]> — the single-value common case is allocation-free; multi-value is supported per Kaci & van der Torre 2008. Empty set means "promotes no value" (defeats unconditionally under VAF semantics). → Full docs

Audience​

A strict partial order over values, represented as ranked tiers. Audience::total([life, property]) produces a total order; Audience::from_tiers(vec![vec![life, liberty], vec![property]]) allows intra-tier ties. Public rank(&value) -> Option<usize> for consumer code. → Full docs

ValueBasedFramework<A>​

A Dung framework (ArgumentationFramework<A>) plus a ValueAssignment<A>. Audience-conditioned acceptance via defeat_graph(audience), accepted_for(audience, arg), grounded_for(audience). Pareto-defeating rule: A defeats B iff for every value B promotes, some value A promotes is not strictly less-preferred under the audience. → Full docs

MultiAudience​

Multi-character consensus queries. MultiAudience::new(&[alice_audience, bob_audience]) then common_grounded(&vaf) returns arguments grounded under every audience — the council-style consensus answer. → Full docs

Error​

Error enum: Dung(#[from] argumentation::Error), AudienceTooLarge { values, limit } (returned past 6 distinct values for subjective/objective acceptance), ArgumentNotFound(String), ApxParse { line, reason }. → Full docs

Key functions / methods​

FunctionReturnsWhat it does
ValueBasedFramework::new(base, values)SelfConstruct from a Dung framework and a value assignment.
vaf.defeat_graph(&audience)Result<ArgumentationFramework<A>, Error>Build the audience-conditioned defeat graph.
vaf.defeats(&attacker, &target, &audience)boolPareto-defeating rule check.
vaf.accepted_for(&audience, &arg)Result<bool, Error>Credulous acceptance under one audience (preferred-extension membership).
vaf.grounded_for(&audience)Result<HashSet<A>, Error>Grounded extension under one audience (delegates to upstream grounded_extension()).
vaf.subjectively_accepted(&arg)Result<bool, Error>Accepted by some audience (NP-complete; capped at 6 values).
vaf.objectively_accepted(&arg)Result<bool, Error>Accepted by every audience (co-NP-complete; capped at 6 values).
MultiAudience::new(&audiences)SelfConstruct from a slice of audiences.
multi.common_grounded(&vaf)Result<HashSet<A>, Error>Intersection of grounded extensions across all audiences.
multi.common_credulous(&vaf)Result<HashSet<A>, Error>Intersection of credulous-acceptance sets across all audiences.
from_scheme_instances(instances, to_arg)ValueAssignment<A>Extract value bindings from argument_from_values Walton-scheme instances.
apx::from_apx(input)Result<(ValueBasedFramework<String>, Audience), Error>Parse ASPARTIX-compatible APX text.
apx::to_apx(&vaf, &audience)StringSerialise to APX.

Constants​

acceptance::ENUMERATION_LIMIT​

The hard cap (currently 6) on distinct values for subjective/objective acceptance. Past this, methods return Error::AudienceTooLarge per Dunne & Bench-Capon (2004) complexity bounds.

scheme_bridge::DEFAULT_VALUES_SCHEME_NAME​

The default-catalog name ("Argument from Values") compared against SchemeInstance.scheme_name. Use from_scheme_instances_with_name to target a custom scheme name.

Errors​

Error::Dung(argumentation::Error)​

Wrapped error from underlying Dung framework operations (e.g., framework-too-large for subset enumeration).

Error::AudienceTooLarge { values, limit }​

subjectively_accepted/objectively_accepted bail out when distinct values exceed ENUMERATION_LIMIT. Use a fixed-audience query (accepted_for) instead.

Error::ArgumentNotFound(String)​

An argument referenced in an attack edge is not registered in the underlying framework.

Error::ApxParse { line, reason }​

APX text input failed to parse. line is 1-indexed.

See also​