wai-quantum: any exercise is checked as a lesson is (engine::course::check_exercise) #645

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dcharlot merged 11 commits from wai/quantum-check-exercise into main 2026-11-06 15:15:59 -05:00

Conversation 0 Commits 11 Files changed 8 +656 -82

2026-11-06

Transaction Science

wai-quantum: say the exercise constraints' new length is a change ...

`wai breaking` reported engine::course::CONSTRAINTS going from 6 to 8 entries
unacknowledged, so the change entry now says so.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

81d3ecd16e

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2026-11-06 14:54:10 -05:00

Transaction Science

Merge remote-tracking branch 'origin/main' into wai/quantum-check-exercise

0f727a2176

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2026-11-06 14:53:43 -05:00

Transaction Science

wai-quantum: an injected error is corrected from the qubits, never read: the error-correction lessons check behaviour ...

The second review found finding 1 closed only for undeclared inputs. A program that
declared `input uint err;` and never used it passed the bit-flip lesson at proof, and
one that branched on the classical err passed the syndrome lesson.

A new constraint, `inject`, names the input whose value is the qubit an error flips.
The cases' programs may then differ in that one gate alone, an x on the qubit the case
names, every other gate, measurement and step the same (course::injected). So the error
is in the quantum state, the program cannot read it classically, and what finds and
corrects it is the program's quantum operations, the same in every case. A program
that never applies the error, reads it elsewhere, or flips another qubit fails, saying
which. A second, `qubits` ({"max": n}), closes the last way round: an answer kept on a
qubit no error reaches. bit-flip-code and syndrome set both; their solutions and wrong
answers keep their results. The exercise schema names both, and a case set an
injection cannot be made from is refused.

Test an_injected_error_is_corrected_from_the_qubits_and_never_read, failing on
ba59c776e for the reason it states (the declared, unused input passed bit-flip-code).
Course tests 13 -> 14 in wai-quantum-docs.yml.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

12496404b5

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2026-11-06 07:58:36 -05:00

Transaction Science

Merge main into wai/quantum-check-exercise ...

Co-Authored-By: Claude Opus 5.5 <[email protected]>

ba59c776eb

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2026-11-06 03:17:44 -05:00

Transaction Science

wai-quantum: a T count, a two-qubit count and an estimate's bound are "at most n" alone ...

The course words these bounds as "at most n" (constraint.t_count, two_qubit, estimate),
and the check read a min too: {"t_count": {"min": 2}} showed the model "at most ? T and
T† gates" while it failed every program with fewer than two. The reader now takes
{"max": n} alone for them (engine::course::at_most), and exercise.v1.json says so
($defs/at_most), with the T count's description saying how T gates are counted. No
lesson uses a min there.

Found sweeping the review's family of claims the check makes that the code does not keep.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

423af2a325

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2026-11-06 03:09:51 -05:00

Transaction Science

wai-quantum: check_exercise reads its exercise first, binds every case's inputs, and counts T gates as gates ...

A check of an exercise that is no lesson's held vacuously where it read nothing, and
the writer makes that check the only gate on a pass. Now:

- engine::course::exercise_form holds a document to a lesson's form as far as a check
  reads it, and check_exercise refuses what it refuses before anything runs: a bound
  that is not whole numbers, a constraint or field the course does not name, a job
  beyond shots, seed and noise (a non-object job panicked the check; a repair or
  dyadic_bits made the engine prove another program than the one recorded), more than
  MOST_CASES (16) cases or MOST_INTENTS (8) intents. read_exercise shares the same
  reading, and a lesson's cases are still named in every locale.
- A case's inputs bind: a program that does not declare one is refused in that case
  (Q114), where it ran without it (the bit-flip lesson passed with no flip). A case
  whose intent is null takes the exercise's, and a case named with one string is
  shown by it.
- The constraints hold in every case's program, not the first one's, and a broken one
  names its case.
- t_count counts T gates, not names: p and rz by an odd multiple of pi/4 count one, a
  Clifford gate none, and any other gate does not hold to a T count. A three-qubit gate
  does not hold to a two-qubit count. The t-count lesson passed with every T written as
  p(pi/4).

Three tests, each failing on the branch's previous head for the reason it states
(13015f77a: a {"t_count": 0} bound was checked and passed; the no-flip program passed
the bit-flip lesson; the respelled t-count answer passed): course tests 10 -> 13 in
wai-quantum-docs.yml, run on Linux x86_64 and macOS aarch64.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

4dcd8ff4a5

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2026-11-06 02:47:34 -05:00

2026-11-05

Transaction Science

Merge main into wai/quantum-check-exercise ...

Main's two newer commits (the marks, #653) touch nothing this branch does.
No conflict.

Co-Authored-By: Claude Fable 5.1 <[email protected]>

13015f77af

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2026-11-05 17:25:09 -05:00

Transaction Science

wai-quantum: check_exercise's changelog entry is a file of wai/changes/ ...

Main now takes one file an entry (wai/changes/README.md), and its
repository checks fail a pull request opened since that adds to the head
of wai/CHANGELOG.md, which is what this branch did. The entry moves, word
for word, to wai/changes/2026-11-05-quantum-any-exercise-checked-as-lesson.md,
and wai/CHANGELOG.md is main's again.

Co-Authored-By: Claude Fable 5.1 <[email protected]>

eef9fa1095

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2026-11-05 16:55:39 -05:00

Transaction Science

Merge main into wai/quantum-check-exercise ...

Main gained fourteen commits since this branch was cut, among them the
changelog's new layout (one entry a file under wai/changes/). Nothing
conflicted; the entry this branch added to the head of wai/CHANGELOG.md
moves to a file in the next commit.

Co-Authored-By: Claude Fable 5.1 <[email protected]>

4663a66178

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2026-11-05 16:55:22 -05:00

Transaction Science

wai-quantum-docs.yml: the course's new test is required by name, and its count is ten ...

The workflow pins how many course tests pass and names each one, since a module filter is satisfied
by any one test. check_exercise added a tenth, so the step failed with every test passing.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

af83fbbe9f

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2026-11-05 10:46:59 -05:00

Transaction Science

wai-quantum: any exercise is checked as a lesson is (engine::course::check_exercise) ...

The course's check held a program to a lesson's exercise: its cases and intents, its constraints,
the engine's verdict at each, and what went wrong in words. Only the lesson lookup tied it to the
course. check_exercise takes the exercise as a document in the course's own form
(wai.quantum.exercise/1) and checks a program against it the same way, with `lesson` null.

It is the first step toward the job service writing a program for an intent: each attempt is held
to the task as a lesson's answer is, and what went wrong is the feedback for the next attempt.

check now finds its lesson and calls the same function, so a lesson's check is the same bytes as
before. A new test holds both:
- a lesson's own exercise, given as a document, checks byte for byte as the lesson does, for a
  right and a wrong program;
- an exercise written from nothing but a distribution passes a Bell pair by proof and fails a
  program without its CNOT, naming the distribution.

The course's ten tests pass (cargo test --features full --lib engine::course).

Co-Authored-By: Claude Opus 5.5 <[email protected]>

898793622e

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2026-11-05 07:47:19 -05:00