Crate clinlat 

clinlat — Clinical Lattice Types

A Rust substrate for symbolic clinical decision-making based on refinable hypothesis lattices and sound deduction operators.

Overview

The clinlat crate provides:

• Hyp: A partially ordered set (poset) of clinical hypotheses, ordered by refinement.
• Outcome<H, A>: A sum type for operator results (refined hypothesis or abstention).
• Deduction operators: Sound functions that refine hypotheses using clinical evidence (e.g., sofa::SofaRespOperator for respiratory dysfunction severity).

Architecture

Hypotheses and Refinement

A Hyp represents a set of clinical atoms at some level of specificity. Hypotheses are ordered by refinement: h1 ⊑ h2 (h1 refines h2) means h1 is more specific.

let unknown = Hyp::unknown();  // Top element: no information.
let specific = Hyp::new(vec!["sofa_score_3"]);  // More specific.
assert!(specific < unknown);  // Refinement ordering.

Operators

An Operator takes a hypothesis and evidence, producing an Outcome:

impl Operator for MyOperator {
    fn apply(&self, h: &Hyp, e: &Evidence) -> Outcome<Hyp, AbstainReason> {
        // Refine h using evidence e, or abstain with a reason.
    }
}

Operators are sound by construction: they satisfy three properties (DEF-PS-08):

1. Refinement monotonicity: Hypothesis specificity never decreases.
2. No spurious refinement: Output never exceeds evidence justification.
3. Abstention purity: Abstention is structural, not error handling.

SOFA-3 Respiratory Scoring

The sofa module implements one operator: SOFA-3 respiratory severity (PaO₂/FiO₂ ratio).

let evidence = SofaRespEvidence::new(350.0, 1.0, false);
let ratio = evidence.pao2_fio2_ratio().unwrap();
let score = score_from_ratio(ratio, false);  // Maps to SOFA score.
assert_eq!(score, Some(1));

v0.1.0 Simplifications

• AtomId is &'static str; real ontology binding (SNOMED CT, RxNorm, LOINC, ICD-11) is deferred to v0.2.
• operator::Evidence is a unit type in the generic trait; concrete operators (like sofa::SofaRespOperator) define richer evidence types.
• Provenance is unit (); timestamped lineage is deferred to v0.2.

References

• Position: Substrate-First Clinical AI (NOTE.md § 4A–4D).
• Formalization: SPEC.md § 2 (patient-state substrate).
• SOFA-3: Vincent et al. (1996), Singer et al. (2016, Sepsis-3).

Re-exports

pub use abstain::AbstainReason;

pub use hyp::AtomId;

pub use hyp::Hyp;

pub use operator::Operator;

pub use outcome::Outcome;

pub use sofa::SofaRespEvidence;

pub use sofa::SofaRespHypothesis;

pub use sofa::SofaRespOperator;

Modules

abstain

Abstention reasons for deduction operators.

hyp

Clinical hypotheses as a refinable poset.

operator

Deduction operators on hypotheses.

outcome

Operator outcome types: refined hypothesis or abstention.

sofa

SOFA-3 respiratory component (PaO₂/FiO₂ ratio) deduction operator.