qadiya (قضية) — Classify + Dispatch under Constraint-Driven Cases

Part of the Mizan stack — the Arabic-first reliability scale for AI agents.

The third + fourth primitives of the reversible-agent-operations pattern: case classification under a constraint set, and dispatch to registered procedures.

What it does

Given a list of constraints (e.g., "operation type", "target scope", "reversibility"), qadiya enumerates the Cartesian product of constraint values, prunes infeasible combinations, and gives you a registry. You register one procedure per surviving case. dispatch() classifies an incoming input by evaluating constraints, then runs the registered procedure for the matching case. If no case matches, it raises — never silently falls through to a "general" handler.

from qadiya import Constraint, CaseRegistry, Dispatch

c_op = Constraint("op", values=("read", "write"),
                   evaluate=lambda r: r["op"])
c_target = Constraint("target", values=("user_file", "system_file"),
                       evaluate=lambda r: r["target"])
c_in_repo = Constraint("in_repo", values=(True, False),
                        evaluate=lambda r: r["in_repo"])

# Pruning: writes outside the repo are infeasible (escalate path)
def feasible(d):
    return not (d["op"] == "write" and not d["in_repo"])

reg = CaseRegistry(constraints=[c_op, c_target, c_in_repo], feasible=feasible)

# 2 × 2 × 2 = 8 combinations; pruning leaves 6
assert reg.case_count() == 6

# Register a procedure for every surviving case
for case in reg.cases:
    reg.register(case.case_id, make_handler_for(case))
reg.verify_complete()  # raises if any case is unhandled

dispatch = Dispatch(registry=reg)
result = dispatch({"op": "read", "target": "user_file", "in_repo": True})
# DispatchResult(outcome=DISPATCHED, case_id="op=read|target=user_file|in_repo=True", output=...)

Why this is the missing primitive

Agent frameworks have intent routers, skill registries, and tool-call dispatchers. They lack the constraint-driven enumeration step. With qadiya:

• Cases are generated, not invented. The constraint Cartesian product produces a complete, verifiable enumeration.
• Infeasible combinations are explicitly pruned, not silently merged with feasible ones.
• Every case must be registered or escalated — verify_complete() raises if any case is unhandled. There is no implicit "default fallback procedure."
• Classification is deterministic — same input always maps to the same case_id.

Properties

1. Determinism — same input → same case_id every time.
2. Completeness verification — verify_complete() ensures no case is silently dropped.
3. Explicit escalation — cases that should not run automatically must be marked with .escalate(). Silent fallback is forbidden.
4. No generation outside procedures — qadiya itself produces no value. It only routes inputs to registered procedures.

Install

pip install -e .

Tests

pytest tests/ -v

15/15 pass on Python 3.10+, including a worked end-to-end example with 4 binary constraints, feasibility pruning, complete coverage verification, and round-trip dispatch.

How it composes with jabr and muqabalah

The three libraries form the four primitives of the pattern:

input
  │
  ▼
jabr.restore()      ← Restore: insert missing terms (al-jabr)
  │
  ▼
muqabalah.balance() ← Balance: cancel duplicates, fail-loud on contradictions
  │
  ▼
qadiya.classify()   ← Classify: which canonical case is this?
  │
  ▼
qadiya.dispatch()   ← Dispatch: run the registered procedure for that case
  │
  ▼
output

Each stage is reversible (where applicable), audited, and independently testable. Together they implement the discipline: every transformation an agent performs is a Restore, a Balance, or a Dispatch; every Restore and Balance preserves the original meaning recoverably; every Dispatch is the only place new value is created.

Failure modes

See FAILURES.md.

License

MIT.