1. Geometric selection
Requests and models are compared in a learned SPD metric, so fit is anisotropic rather than raw Euclidean proximity.
Incomplete by construction
Compitum is a self-published research artifact for LLM routing: learned SPD geometry, feasibility-first constraints, and Lyapunov-style bounded updates, with each structural claim pinned to a runnable falsification test.
Contribution map
The paper is deliberately narrower than a benchmark victory. It offers a concrete routing construction, states the assumptions under which the energy behaves like a Lyapunov functional, and makes the claims executable.
Requests and models are compared in a learned SPD metric, so fit is anisotropic rather than raw Euclidean proximity.
Region, policy, and capability constraints filter the action set before utility optimization, so infeasible models cannot win.
Line search, trust-radius control, and update strides are mapped to property-based tests with named falsification criteria.
“All of us is limited. None of us has all the answers. Come develop with us.”
Pipeline
Compitum never sees true quality directly. It acts from coarse predictors, hard constraints, and bounded updates, then emits a certificate that can be audited.
Embed prompt as a finite state vector x.
Score each model through M = LL^T + delta I.
Minimize quality, latency, cost, distance, and evidence tradeoffs.
Reject infeasible actions before selecting the argmin.
Return route, diagnostics, drift status, and falsifiable traces.
Figures
The diagrams below are inline SVG with text alternatives, so they survive static hosting, print cleanly, and remain inspectable by assistive technology.
Falsification harness
A passing suite does not prove the framework correct. It proves these named properties hold across generated cases. That smaller claim is the point.
git clone https://github.com/PaulTiffany/compitum.git cd compitum pip install -e . HYPOTHESIS_PROFILE=ci pytest -q tests/invariants
| ID | Prediction | Falsified if | Test family |
|---|---|---|---|
| P1 | Learned metric M is strictly SPD. | Any eigenvalue is non-positive for delta > 0. | test_invariants_metric |
| P2 | Metric distance obeys symmetry, triangle inequality, and ray monotonicity. | Any axiom fails beyond tolerance. | metric_triangle, metric_ray |
| P3 | Metric line-search updates do not increase surrogate energy. | Accepted step raises E. | test_invariants_lg |
| P4 | Controller energy decays under zero drift. | V_ctrl rises when error proxy is zero. | test_invariants_control_sy |
| P5 | Learning is isolated between update strides. | Metric factor changes before stride boundary. | test_invariants_control_sy |
| P6 | Routed distance proxy does not increase over updates. | Final proxy exceeds initial proxy. | test_invariants_srmf_lyapunov |
| P7 | Selection is feasibility-monotone and dual slack is near zero at boundary. | Infeasible model selected or boundary slack is large. | test_invariants_constraints |
| P8 | Routing is deterministic; paraphrase behavior is bounded and explainable. | Identical input yields different route or flip budget is exceeded. | router_determinism, test_paraphrase_* |
Scope
The paper is strongest where it refuses to overclaim. The artifact does not assert a global stability theorem, a general benchmark win, or a universal potential function.
Positive result: on the synthetic routing benchmark, the geometry can buy utility-per-dollar at zero violations when latency is acceptable.
Negative result: on flat engineered-feature materials data, the curved-metric advantage disappears. The method should not manufacture curvature where the chart is wrong.
A concrete construction, local surrogate non-increase, an executable falsification harness, and a reproducible empirical reading.
Global asymptotic convergence, safety by stability alone, or a universal benchmark victory.
This is the routing instance of a broader bounded-observer program alongside The Wicked Prior and compitum.space.