practice — discretized parameter axes: named levels, never a number (owner-approved 2026-09-29)

Contracts: LadderRung 0-4, CueDistance 0-2, Presentation theory|
application; PracticeParams carries the three named levels. Doc
comments hold the three definition tables verbatim (rung names +
definitions from the ladder doctrine; cue levels; presentation
levels).

Core: LADDER_RUNGS/CUE_LEVELS/PRESENTATIONS tables in src/core/
practice.ts (definitions verbatim) — ONE source spoken by the agents'
prompts, the dialog's stepped controls, and the exam header; core
barrel re-exports practice.ts (pure domain, browser-safe).

Agents: Part I's ladder intro now 'five rungs, numbered; the request
arrives as a rung' with bullets numbered 0-4 (definitions untouched);
Part III's parameters block replaced with the named-level doctrine
(rung = exact class, no continuum; cue counts lesson examples AND
previous problems' situations; presentation dresses, never changes);
partitioner's RESPECT THE PARAMETERS replaced (low rungs = many small
assignments, high = larger; far cue makes confusables-together MORE
important; presentation does not shape the partition). renderParams
outputs the exact named-level block. Anchor/0..1 language swept dead.

Service + store: strict union validation — floats between levels,
out-of-range, wrong strings, legacy dial shapes all 400 at the API
and fail isProblemSet (legacy sets skipped from lists; no migration —
data/practice is disposable scratch, owner wipes before testing).

UI: dialog = 5-detent ladder slider + 3-detent cue slider (each shows
the level NAME + one-line definition) + Theory|Application segmented
toggle; defaults rung 2 / cue 1 / theory; Create posts the new shape.
Exam header gains the levels line ('Direct exercise · Adjacent
context · Theory').

Tests: renderParams exact-block pin; strict-validation pins (new
tests/practice-service.test.ts — bad unions 400, legacy shape 400);
store pins (legacy floats + 2.5 rung fail); render pins (detents +
names + definitions, defaults, detent-swap, toggle active segment,
levels line); every params fixture moved off floats. 1138/1138, tsc
0, lint 0, build 0.

Docs: architecture.md — discretization paragraph (compact tables,
named-level invocation, defaults, one-table source), UI mentions;
README axes sentence.

src/core/contracts/practice.ts

@@ -49,17 +49,57 @@ export interface ReasoningChain {
 	conclusion: string;
 }
 
-/** The three dials every problem set is configured with (owner, 2026-09-29)
- *  — all 0..1, interpreted by the agents against the framework's axes. */
+/** The main axis, discretized (owner, 2026-09-29 — named levels, never
+ *  a number to interpolate; definitions verbatim from the ladder
+ *  doctrine): */
+export type LadderRung = 0 | 1 | 2 | 3 | 4;
+
+/** Cue distance from every situation the learner has already met — the
+ *  lesson's own examples AND every previous problem's situation
+ *  (definitions owner-approved 2026-09-29): */
+export type CueDistance = 0 | 1 | 2;
+
+/** How the situation is dressed — never changes the rung or the cue
+ *  distance: */
+export type Presentation = "theory" | "application";
+
+/** The three settings every problem set is configured with (owner,
+ *  2026-09-29) — each a named level, invoked as that level exactly:
+ *
+ *  THE LADDER (the main axis, bottom to top):
+ *    0 Worked example — the solution is shown; nothing is demanded. An
+ *      installation object; nothing yet to recall.
+ *    1 Completion — the path is shown with a gap; the learner supplies
+ *      one step. What to recall is nearly announced.
+ *    2 Direct exercise — one step, no hint, but the situation makes the
+ *      applicable proposition unmistakable. Trains execution, not choosing.
+ *    3 Composition — several steps, chained; the path is narrow but must
+ *      be held and run.
+ *    4 Path-finding — several steps, the path concealed, distractors
+ *      present, the statement suggesting wrong methods. The competition
+ *      shape.
+ *
+ *  THE CUE DISTANCE:
+ *    0 Lesson context — the textbook/toy-example shape in the teaching's
+ *      own framing.
+ *    1 Adjacent context — a genuinely new situation built from the
+ *      teaching's own world — same domain, different setup/packaging.
+ *    2 Far context — as far from the typical cue as recognition allows,
+ *      the edge of the recognizable band; the proposition must still
+ *      genuinely apply, and the learner must be able to find it by looking.
+ *
+ *  THE PRESENTATION:
+ *    theory — the subject's own terms — symbols, formal objects, native
+ *      vocabulary.
+ *    application — a concrete worldly affair — a case, episode, system,
+ *      or story — in which the proposition's structure appears in the wild. */
 export interface PracticeParams {
-	/** Search-to-solution ratio — the main axis: flashcard recall (0) to
-	 *  competition problem (1). */
-	searchSolutionRatio: number;
-	/** Cue distance from every situation already used (0 = near the
-	 *  lesson, 1 = far transfer — still inside the recognizable band). */
-	cueDistance: number;
-	/** Presentation axis: pure theory (0) to real-world application (1). */
-	presentation: number;
+	/** Which class of problem to build — exactly that rung. */
+	ladderRung: LadderRung;
+	/** How far the situation sits from the cues already met. */
+	cueDistance: CueDistance;
+	/** How the situation is dressed. */
+	presentation: Presentation;
 }
 
 /** Where a set stands in the two-stage run. The set is PERSISTED at
@@ -119,8 +159,8 @@ export interface Problem {
 export interface ProblemSet {
 	/** "ps_" + ts36 + rand — store-assigned. */
 	id: string;
-	/** Display label — auto-generated (the session's title, or
-	 *  date-based). */
+	/** Display label — the picked cluster's label, or the dated
+	 *  default. */
 	title: string;
 	createdAt: string;
 	params: PracticeParams;

src/core/index.ts

@@ -31,6 +31,7 @@ export * from "./phases.ts";
 export * from "./pending.ts";
 export * from "./prompt-segments.ts";
 export * from "./math-delims.ts";
+export * from "./practice.ts";
 // Wave B (owner-approved 2026-09-26): the native record (LhMessage), the
 // and the input-events contract — all
 // pure logic, browser-safe.

src/core/practice.ts

@@ -11,7 +11,30 @@
  * the union of the problems' chains must equal the set's chains; the
  * partitioner's submit is validated against it.
  */
-import type { GraphEdge, GraphNode, Problem, ReasoningChain } from "./contracts.ts";
+import type { CueDistance, GraphEdge, GraphNode, LadderRung, Presentation, Problem, ReasoningChain } from "./contracts.ts";
+
+/** The named levels (owner-approved 2026-09-29) — definitions verbatim
+ *  from the ladder doctrine / the contract's tables. The UI's stepped
+ *  controls, the exam header's levels line, and the agents' prompt
+ *  rendering all speak these names — never a bare number. */
+export const LADDER_RUNGS: Record<LadderRung, { name: string; definition: string }> = {
+	0: { name: "Worked example", definition: "the solution is shown; nothing is demanded. An installation object; nothing yet to recall." },
+	1: { name: "Completion", definition: "the path is shown with a gap; the learner supplies one step. What to recall is nearly announced." },
+	2: { name: "Direct exercise", definition: "one step, no hint, but the situation makes the applicable proposition unmistakable. Trains execution, not choosing." },
+	3: { name: "Composition", definition: "several steps, chained; the path is narrow but must be held and run." },
+	4: { name: "Path-finding", definition: "several steps, the path concealed, distractors present, the statement suggesting wrong methods. The competition shape." },
+};
+
+export const CUE_LEVELS: Record<CueDistance, { name: string; definition: string }> = {
+	0: { name: "Lesson context", definition: "the textbook/toy-example shape in the teaching's own framing." },
+	1: { name: "Adjacent context", definition: "a genuinely new situation built from the teaching's own world — same domain, different setup/packaging." },
+	2: { name: "Far context", definition: "as far from the typical cue as recognition allows, the edge of the recognizable band — the proposition must still genuinely apply, and the learner must be able to find it by looking." },
+};
+
+export const PRESENTATIONS: Record<Presentation, { name: string; definition: string }> = {
+	theory: { name: "Theory", definition: "the subject's own terms — symbols, formal objects, native vocabulary." },
+	application: { name: "Application", definition: "a concrete worldly affair — a case, episode, system, or story — in which the proposition's structure appears in the wild." },
+};
 
 /** The selection's follows-edges as chains: every edge into a node joins
  *  that node's (one) chain; a node with no in- AND no out-follows-edge in