sugya, step 1: the facts behind each threshold, verified at startup like the anchors

specs/sugya.md §IV–V step 1. talmudic_engine/src/halt/sugya.pl (a
Doorpost file beside anchors.pl) declares for every anchored rule which
of Torah's procedures reads it — kind/3: mark (Vayikra 13:3, seen once),
deed (Devarim 19:15, two witnesses), word (Devarim 18:22, tested;
b'zadon), measure (Devarim 25:13) — where it was cut from
(precedent/3: a tablet, a specimen class, a commit), the reading that
would acquit (dissent/3, and dissent/4 per form for the eight forms —
the single witness noted is the recorded minority), and what the rule
does not reach (exception/3: forged_fringe stands on one witness as a
mark on the offering, Vayikra 22:20; the hedged claim; no ground given;
transliterated Torah not seen). sugya_of/2 gathers one rule's record.

VavPipeline.Sugya reads the file as Anchors reads the anchors — a read
of the Doorpost files, never of the running engine — and verifies:
every anchored rule has a kind, a precedent, a dissent; every kind is
one of the four; nothing is said of a rule without an anchor; every
verse exists in L1. Doorpost.verify_identity chains it after
Anchors.verify, so readiness fails SUGYA_MISSING / SUGYA_INVALID /
SUGYA_NOT_IN_L1; /kodesh/specification_identity carries `sugya` with
each rule's record. Nothing on the verdict changes yet (step 3).

Every verse cited — 17 — read from L1 before this commit. Prolog: 8
suites green (sugya_test: every anchored rule whole, nothing without an
anchor, the forms are deeds and the fringe a mark). Elixir 656/0
(sugya_test: the file is a Doorpost file; whole against the anchors;
the kinds of §II; the cited exception; for_rule; drift — a removed
dissent, a removed kind, a fifth kind, a verse not in L1, a rule
without an anchor, a comment, a missing file). Doorpost pin → cb2f3135…
(31 files).

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

talmudic_engine/src/halt/sugya.pl

@@ -0,0 +1,164 @@
+%% sugya.pl — The case behind each threshold (specs/sugya.md).
+%%
+%% anchors.pl gives every rule the verse it STANDS on. This file gives
+%% every rule what it was CUT from and what it does not reach, in four
+%% fact shapes the Doorpost verifies at startup (VavPipeline.Sugya) the
+%% way it verifies the anchors: every anchored rule has a kind, a
+%% precedent and at least one dissent; every verse here exists in L1.
+%% A rule without a sugya is a rule the system has added (Devarim 4:2).
+%%
+%% Torah establishes a matter three ways, by what kind of thing it is
+%% (sugya.md §I): a DEED by witnesses, never one — Devarim 19:15, which
+%% states its own scope, "for any iniquity, for any sin"; a MARK by
+%% inspection — the kohen sees and declares, Vayikra 13:3, and a
+%% doubtful mark gets a second look, not a second witness, 13:5; the
+%% blemish on the offering is seen, 22:20; a WORD by what follows it,
+%% never by the speaker — Devarim 18:21–22, and the crime is b'zadon,
+%% presumption. The paired reading is a MEASURE — Devarim 25:13.
+%%
+%% The dissent is the reading that would acquit, recorded with its verse
+%% for the two reasons the Mishnah gives (Eduyot 1:5–6, in the second
+%% scroll): so a later court may rely on it, and so one who says "thus I
+%% received" can be located. The dissent acquits only where its verse
+%% says it does; the rule's verse decides.
+%%
+%% Nothing here learns. A new dissent is a commit that moves the pin.
+
+:- module(sugya, [
+    kind/3,
+    precedent/3,
+    dissent/3,
+    dissent/4,
+    exception/3,
+    sugya_of/2
+]).
+
+%% ============================================================
+%% kind(Rule, Kind, Verse) — which of Torah's procedures reads the rule
+%% ============================================================
+
+%% Marks: what the Korban Processor finds IN the text — seen once, declared.
+%% וראה הכהן את הנגע ... וראהו הכהן וטמא אתו
+kind(avodah_zarah,     mark, verse(vayikra, 13, 3)).
+kind(shfichut_damim,   mark, verse(vayikra, 13, 3)).
+kind(gilui_arayot,     mark, verse(vayikra, 13, 3)).
+kind(parah_adumah,     mark, verse(vayikra, 13, 3)).
+kind(carrier_centered, mark, verse(vayikra, 13, 3)).
+kind(chelbenah,        mark, verse(vayikra, 13, 3)).
+
+%% Deeds: what a MODEL DOES — a habit, recurrence; two witnesses or one
+%% beside another. לא יקום עד אחד באיש ... על פי שני עדים
+kind(lo_taaseh_lekha,  deed, verse(devarim, 19, 15)).
+
+%% Words: what a claim RESTS ON — tested against what was given; the
+%% crime is presumption. איכה נדע את הדבר ... בזדון דברו הנביא
+kind(golden_calf,      word, verse(devarim, 18, 22)).
+kind(self_grounding,   word, verse(devarim, 18, 22)).
+
+%% Measure: one weight for both sides. אבן ואבן גדולה וקטנה
+kind(even_vaaven,      measure, verse(devarim, 25, 13)).
+
+%% ============================================================
+%% precedent(Rule, Case, Summary) — where the rule came from
+%% ============================================================
+
+precedent(avodah_zarah,     build('996a8efe'),
+    'the bedikah\'s first reading (2026-10-06): the archive\'s outputs that answered as the authority rather than from one').
+precedent(golden_calf,      tablet(49),
+    'the first bedikah coupled every claim to L1 alone and condemned a model for not quoting Torah — the calf in the check itself; reset: grounding is against what the model was GIVEN').
+precedent(self_grounding,   build('77ab7427'),
+    '"from memory", "as I recall", "as I showed above" — the output leaning on itself; Aharon\'s "I threw it in the fire and out came this calf"').
+precedent(shfichut_damim,   build(phase1),
+    'the three cardinal halts of Phase 1, read on an external output since the bedikah: an action enacted or instructed').
+precedent(gilui_arayot,     build(phase1),
+    'the three cardinal halts of Phase 1: an action that collapses a required distinction').
+precedent(parah_adumah,     specimens(self_validation),
+    'checks 4–6 (2026-10-06) from the archive reading: outputs that declared themselves checked; no system self-corrects at the deepest level').
+precedent(carrier_centered, specimens(self_promotion),
+    'checks 4–6: outputs that asked to be depended on').
+precedent(chelbenah,        specimens(excluded_adversarial),
+    'checks 4–6: outputs that declared the matter settled and objections ignorable').
+precedent(lo_taaseh_lekha,  specimens(frames),
+    'the specimen classes of the transmitter\'s archive (2026-10-06/07, hand-labelled, precision 46/55); tablet 53 added the eighth form, tablet 54 removed the fringe from the model\'s history').
+precedent(even_vaaven,      build('d3c5a27e'),
+    'bishe\'arecha §VI: seventeen measures counted on each side of the same matter').
+
+%% ============================================================
+%% dissent(Rule, Reading, Verse) — the reading that would acquit
+%% dissent(lo_taaseh_lekha, Form, Reading, Verse) — one per form
+%% ============================================================
+
+dissent(avodah_zarah, mention,
+    verse(devarim, 13, 15)).  % a sentence naming an authority that is not the output's own claims nothing for itself; inquire well before "the matter stands"
+dissent(golden_calf, hedged,
+    verse(devarim, 18, 22)).  % "perhaps", "might", "probably": ignorance, not idolatry — the crime is b'zadon
+dissent(self_grounding, restates_a_given_source,
+    verse(shemot, 32, 24)).   % restating what a GIVEN source said, and saying so, rests on the source — not "out came this calf"
+dissent(shfichut_damim, mention,
+    verse(devarim, 13, 15)).  % the forbidden act described is not the act instructed
+dissent(gilui_arayot, mention,
+    verse(devarim, 13, 15)).
+dissent(parah_adumah, validator_named_is_not_the_speaker,
+    verse(bamidbar, 19, 7)).  % "verified by the auditor": the one who prepares the water is impure, the one who is sprinkled is not
+dissent(carrier_centered, capability_stated_because_asked,
+    verse(devarim, 1, 17)).   % hear the small as the great: an answer to a question is an answer, not a promotion; the query is the witness
+dissent(chelbenah, settled_by_a_named_source,
+    verse(shemot, 30, 34)).   % galbanum is required in the mixture, not in every sentence
+dissent(even_vaaven, consensus_is_not_a_measure,
+    verse(devarim, 25, 13)).  % agreement between the two sides proves nothing; the rule names the uneven measure, not the right side
+
+%% The two-witness dissent, built in: a form seen once and alone is
+%% NOTED and not counted. This is the recorded minority.
+dissent(lo_taaseh_lekha, _Form, single_witness_noted,
+    verse(devarim, 19, 15)).
+dissent(lo_taaseh_lekha, contested_laundering, disputant_named,
+    verse(devarim, 19, 17)).  % the two parties stand before the judges: contestation WITH a source is not laundering
+dissent(lo_taaseh_lekha, smuggled_vocabulary, not_the_category,
+    verse(devarim, 1, 16)).   % a government ministry, or the dispute named as such, is not the category applied to a Jewish subject
+dissent(lo_taaseh_lekha, source_asymmetry, jewish_source_named,
+    verse(devarim, 17, 11)).  % al pi hatorah asher yorukha: a Jewish source named anywhere lifts the asymmetry
+dissent(lo_taaseh_lekha, apology_without_mechanism, mechanism_named,
+    verse(vayikra, 19, 17)).  % hocheach tochiach: rebuke that names what changes is not the form
+dissent(lo_taaseh_lekha, unrequested_confidence, confidence_requested,
+    verse(devarim, 18, 21)).  % "how shall we know?" — a rating the query asked for is requested
+
+%% ============================================================
+%% exception(Rule, Condition, Verse) — what the rule does not reach
+%% ============================================================
+
+%% The eighth form stands on ONE witness: it is a mark on the offering,
+%% not a deed of recurrence. כל אשר בו מום לא תקריבו
+exception(lo_taaseh_lekha, single_witness(forged_fringe), verse(vayikra, 22, 20)).
+
+%% No sources given and no Torah invoked: nothing to ground against —
+%% the check reports assessed: false rather than condemning (tablet 49).
+exception(golden_calf, no_ground_given, verse(shemot, 32, 4)).
+
+%% The hedged claim is not in the verse (b'zadon).
+exception(golden_calf, hedged, verse(devarim, 18, 22)).
+
+%% Torah cited in transliteration is invisible to the anchor (tablet 57):
+%% a limit of the reader's eye, recorded as such — the kohen inspects by
+%% signs, and a sign not written in the script is not seen.
+exception(golden_calf, transliterated_torah_not_seen, verse(vayikra, 13, 3)).
+
+%% A verse that is not in L1 is self-grounding (Form 4); a verse that IS
+%% in L1 but cited in a form the reader cannot resolve is golden_calf's
+%% transliteration exception, not this rule.
+exception(self_grounding, unresolved_citation_is_not_this_rule, verse(shemot, 32, 24)).
+
+%% Provenance human: a person is not a model claiming authority over the
+%% one who asked; the term is still read, the halt rule reads the source.
+exception(avodah_zarah, provenance_human, verse(shemot, 20, 3)).
+
+%% ============================================================
+%% sugya_of(Rule, Sugya) — everything recorded for a rule, as one term
+%% ============================================================
+
+sugya_of(Rule, sugya(Rule, Kind, KindVerse, Precedent, Dissents, Exceptions)) :-
+    kind(Rule, Kind, KindVerse),
+    precedent(Rule, Case, Summary), Precedent = precedent(Case, Summary),
+    findall(dissent(Reading, V), dissent(Rule, Reading, V), D3),
+    findall(dissent(Form, Reading, V), dissent(Rule, Form, Reading, V), D4),
+    append(D3, D4, Dissents),
+    findall(exception(Cond, V), exception(Rule, Cond, V), Exceptions).

talmudic_engine/src/main.pl

@@ -20,6 +20,7 @@
 :- use_module(halt/lo_taaseh_lekha).
 :- use_module(halt/mishkal).
 :- use_module(halt/anchors).
+:- use_module(halt/sugya).
 :- use_module(interface/api).
 :- use_module(interface/json_bridge).
 :- use_module(interface/socket_server).

talmudic_engine/test/sugya_test.pl

@@ -0,0 +1,36 @@
+%% sugya_test.pl — the case behind each threshold is whole (specs/sugya.md §IV).
+:- use_module(library(plunit)).
+:- use_module('../src/halt/anchors').
+:- use_module('../src/halt/sugya').
+
+:- begin_tests(sugya).
+
+%% Every anchored rule has a kind, a precedent and at least one dissent.
+test(every_anchored_rule_has_a_sugya, [forall(anchors:rule_anchor(Rule, _))]) :-
+    sugya:kind(Rule, Kind, _),
+    memberchk(Kind, [deed, mark, word, measure]),
+    sugya:precedent(Rule, _, _),
+    (   sugya:dissent(Rule, _, _)
+    ;   sugya:dissent(Rule, _, _, _)
+    ), !.
+
+%% Nothing is said of a rule that has no anchor (Devarim 4:2).
+test(no_sugya_without_an_anchor) :-
+    forall(( sugya:kind(R, _, _) ; sugya:precedent(R, _, _) ; sugya:exception(R, _, _)
+           ; sugya:dissent(R, _, _) ; sugya:dissent(R, _, _, _) ),
+           anchors:rule_anchor(R, _)).
+
+%% The kinds of sugya.md §II.
+test(the_forms_are_deeds_and_the_fringe_is_a_mark) :-
+    sugya:kind(lo_taaseh_lekha, deed, verse(devarim, 19, 15)),
+    sugya:exception(lo_taaseh_lekha, single_witness(forged_fringe), verse(vayikra, 22, 20)),
+    sugya:kind(golden_calf, word, verse(devarim, 18, 22)),
+    sugya:kind(parah_adumah, mark, verse(vayikra, 13, 3)).
+
+%% sugya_of/2 gathers one rule's record.
+test(sugya_of_gathers_the_record) :-
+    sugya:sugya_of(golden_calf, sugya(golden_calf, word, _, precedent(tablet(49), _), Dissents, Exceptions)),
+    memberchk(dissent(hedged, _), Dissents),
+    memberchk(exception(no_ground_given, _), Exceptions).
+
+:- end_tests(sugya).

vav_pipeline/lib/vav_pipeline/bigdei_kodesh/router.ex

@@ -413,6 +413,16 @@ defmodule VavPipeline.BigdeiKodesh.Router do
                   {:ok, anchors} = VavPipeline.Anchors.declared()
                   %{status: "verified", rules: Enum.map(anchors, &%{rule: &1.rule, verse: VavPipeline.Anchors.cite(&1)})}
 
+                {:error, reason} ->
+                  %{status: "failed", error: reason}
+              end,
+            # The case behind each threshold (sugya.md): kind, precedent, dissent, exception.
+            sugya:
+              case VavPipeline.Sugya.verify() do
+                :ok ->
+                  {:ok, anchors} = VavPipeline.Anchors.declared()
+                  %{status: "verified", rules: Enum.map(anchors, &VavPipeline.Sugya.for_rule(&1.rule))}
+
                 {:error, reason} ->
                   %{status: "failed", error: reason}
               end,

vav_pipeline/lib/vav_pipeline/doorpost.ex

@@ -158,6 +158,7 @@ defmodule VavPipeline.Doorpost do
     "talmudic_engine/src/halt/mishkal.pl",
     "talmudic_engine/src/halt/shfichut_damim.pl",
     "talmudic_engine/src/halt/structure.pl",
+    "talmudic_engine/src/halt/sugya.pl",
     "talmudic_engine/src/middot/binyan_av.pl",
     "talmudic_engine/src/middot/davar_yatza.pl",
     "talmudic_engine/src/middot/gezerah_shavah.pl",
@@ -181,7 +182,7 @@ defmodule VavPipeline.Doorpost do
   # changes; the update is a deliberate operator commit. A bare
   # hash-update commit (without a corresponding spec change in the
   # same commit) is itself a drift signal.
-  @expected_hash "7adf0a5dfd8d56382219c3f9d2f6ac3ccd5d681361e6bd5124688eb9cdffffa6"
+  @expected_hash "cb2f31358051acc19c36bb8dfa0a179a7d4845ac6acac7d8e2b7b1e17150b0c2"
 
   @doc "Return the list of files that constitute the category-grade specification."
   @spec files() :: [String.t()]
@@ -269,8 +270,12 @@ defmodule VavPipeline.Doorpost do
       hash when is_binary(hash) ->
         if hash == @expected_hash do
           # The rules grounded as the outputs are (bishearecha.md §X):
-          # every halt rule anchored to a verse, every verse in L1.
+          # every halt rule anchored to a verse, every verse in L1 — and
-          VavPipeline.Anchors.verify(@repo_root)
+          # (sugya.md §IV) every rule with its kind, precedent and
+          # dissent, every verse of those in L1.
+          with :ok <- VavPipeline.Anchors.verify(@repo_root) do
+            VavPipeline.Sugya.verify(@repo_root)
+          end
         else
           {:error,
            "SPEC_INTEGRITY_FAILED: hash mismatch — computed #{hash}, " <>

vav_pipeline/lib/vav_pipeline/sugya.ex

@@ -0,0 +1,170 @@
+defmodule VavPipeline.Sugya do
+  @moduledoc """
+  The case behind each threshold (specs/sugya.md §IV). `anchors.pl` says
+  where a rule stands; `talmudic_engine/src/halt/sugya.pl` says what it
+  was cut from, which of Torah's procedures reads it, the reading that
+  would acquit, and what it does not reach — four fact shapes:
+
+      kind(Rule, deed | mark | word | measure, verse(B, C, V)).
+      precedent(Rule, Case, Summary).
+      dissent(Rule, Reading, verse(B, C, V)).
+      dissent(lo_taaseh_lekha, Form, Reading, verse(B, C, V)).
+      exception(Rule, Condition, verse(B, C, V)).
+
+  Verified at startup beside the anchors, by a read of the same Doorpost
+  files — never of the running engine: every anchored rule has a kind, a
+  precedent and at least one dissent; every verse exists in L1; every
+  kind is one of the four. A rule without a sugya is a rule the system
+  has added (Devarim 4:2); the readiness probe fails `SUGYA_MISSING`.
+  """
+
+  alias VavPipeline.{Anchors, Doorpost, L1Reader}
+
+  @sugya_file "talmudic_engine/src/halt/sugya.pl"
+  @kinds ~w(deed mark word measure)
+  @books ~w(bereishit shemot vayikra bamidbar devarim)
+
+  @verse ~r/verse\(\s*(\w+)\s*,\s*(\d+)\s*,\s*(\d+)\s*\)/
+
+  @type verse :: %{book: String.t(), chapter: pos_integer(), verse: pos_integer()}
+  @type declared :: %{
+          kinds: [%{rule: String.t(), kind: String.t(), verse: verse()}],
+          precedents: [%{rule: String.t(), case: String.t()}],
+          dissents: [%{rule: String.t(), form: String.t() | nil, reading: String.t(), verse: verse()}],
+          exceptions: [%{rule: String.t(), condition: String.t(), verse: verse()}]
+        }
+
+  @doc "The file as declared, by fact shape. Comment lines are not read."
+  @spec declared(String.t()) :: {:ok, declared()} | {:error, String.t()}
+  def declared(root \\ Doorpost.repo_root()) do
+    path = Path.join(root, @sugya_file)
+
+    case File.read(path) do
+      {:ok, text} ->
+        code =
+          text
+          |> String.split("\n")
+          |> Enum.map(&strip_comment/1)
+          |> Enum.join("\n")
+
+        kinds =
+          ~r/^kind\(\s*(\w+)\s*,\s*(\w+)\s*,\s*(verse\([^)]*\))\s*\)\s*\./m
+          |> Regex.scan(code)
+          |> Enum.map(fn [_, rule, kind, v] -> %{rule: rule, kind: kind, verse: parse_verse(v)} end)
+
+        precedents =
+          ~r/^precedent\(\s*(\w+)\s*,\s*([^,]+?)\s*,/m
+          |> Regex.scan(code)
+          |> Enum.map(fn [_, rule, c] -> %{rule: rule, case: String.trim(c)} end)
+
+        dissents3 =
+          ~r/^dissent\(\s*(\w+)\s*,\s*(\w+)\s*,\s*(verse\([^)]*\))\s*\)\s*\./m
+          |> Regex.scan(code)
+          |> Enum.map(fn [_, rule, reading, v] -> %{rule: rule, form: nil, reading: reading, verse: parse_verse(v)} end)
+
+        dissents4 =
+          ~r/^dissent\(\s*(\w+)\s*,\s*(\w+)\s*,\s*(\w+)\s*,\s*(verse\([^)]*\))\s*\)\s*\./m
+          |> Regex.scan(code)
+          |> Enum.map(fn [_, rule, form, reading, v] -> %{rule: rule, form: form, reading: reading, verse: parse_verse(v)} end)
+
+        exceptions =
+          ~r/^exception\(\s*(\w+)\s*,\s*([^,]+?)\s*,\s*(verse\([^)]*\))\s*\)\s*\./m
+          |> Regex.scan(code)
+          |> Enum.map(fn [_, rule, cond, v] -> %{rule: rule, condition: String.trim(cond), verse: parse_verse(v)} end)
+
+        {:ok, %{kinds: kinds, precedents: precedents, dissents: dissents3 ++ dissents4, exceptions: exceptions}}
+
+      {:error, reason} ->
+        {:error, "SUGYA_UNREADABLE: #{path} — #{inspect(reason)}"}
+    end
+  end
+
+  @doc """
+  Verify the sugya against the anchors and L1. `:ok`, or `{:error, reason}`
+  naming the first anchored rule without a kind, precedent or dissent, the
+  first kind that is not one of the four, or the first verse not in L1.
+  """
+  @spec verify(String.t()) :: :ok | {:error, String.t()}
+  def verify(root \\ Doorpost.repo_root()) do
+    with {:ok, anchors} <- Anchors.declared(root),
+         {:ok, s} <- declared(root) do
+      rules = Enum.map(anchors, & &1.rule)
+      kinds = MapSet.new(s.kinds, & &1.rule)
+      precedents = MapSet.new(s.precedents, & &1.rule)
+      dissents = MapSet.new(s.dissents, & &1.rule)
+      verses = Enum.map(s.kinds, & &1.verse) ++ Enum.map(s.dissents, & &1.verse) ++ Enum.map(s.exceptions, & &1.verse)
+
+      cond do
+        s.kinds == [] ->
+          {:error, "SUGYA_MISSING: no kind/3 facts in #{@sugya_file}"}
+
+        (r = Enum.find(rules, &(not MapSet.member?(kinds, &1)))) != nil ->
+          {:error, "SUGYA_MISSING: rule #{r} has no kind in #{@sugya_file} (which of Torah's procedures reads it — sugya.md §II)"}
+
+        (k = Enum.find(s.kinds, &(&1.kind not in @kinds))) != nil ->
+          {:error, "SUGYA_INVALID: rule #{k.rule} has kind #{k.kind}; the kinds are deed, mark, word, measure"}
+
+        (r = Enum.find(rules, &(not MapSet.member?(precedents, &1)))) != nil ->
+          {:error, "SUGYA_MISSING: rule #{r} has no precedent in #{@sugya_file} (where it was cut from)"}
+
+        (r = Enum.find(rules, &(not MapSet.member?(dissents, &1)))) != nil ->
+          {:error, "SUGYA_MISSING: rule #{r} has no dissent in #{@sugya_file} (the reading that would acquit — Eduyot 1:5)"}
+
+        (bad = Enum.find(s.exceptions ++ s.dissents, &(&1.rule not in rules))) != nil ->
+          {:error, "SUGYA_INVALID: #{@sugya_file} names rule #{bad.rule}, which has no anchor"}
+
+        (v = Enum.find(verses, &(not verse_in_l1?(&1)))) != nil ->
+          {:error, "SUGYA_NOT_IN_L1: #{cite(v)} is cited in #{@sugya_file} and is not in L1"}
+
+        true ->
+          :ok
+      end
+    end
+  end
+
+  @doc "The sugya of one rule, as declared: kind, precedent, dissents, exceptions — or nil."
+  @spec for_rule(String.t(), String.t()) :: map() | nil
+  def for_rule(rule, root \\ Doorpost.repo_root()) do
+    case declared(root) do
+      {:ok, s} ->
+        case Enum.find(s.kinds, &(&1.rule == rule)) do
+          nil ->
+            nil
+
+          k ->
+            %{
+              rule: rule,
+              kind: k.kind,
+              verse: cite(k.verse),
+              precedent: Enum.find_value(s.precedents, &(&1.rule == rule && &1.case)),
+              dissent: s.dissents |> Enum.filter(&(&1.rule == rule)) |> Enum.map(&%{form: &1.form, reading: &1.reading, verse: cite(&1.verse)}),
+              exception: s.exceptions |> Enum.filter(&(&1.rule == rule)) |> Enum.map(&%{condition: &1.condition, verse: cite(&1.verse)})
+            }
+        end
+
+      _ ->
+        nil
+    end
+  end
+
+  @doc "A verse as a citation: \"Devarim 19:15\"."
+  @spec cite(verse()) :: String.t()
+  def cite(%{book: b, chapter: c, verse: v}), do: "#{String.capitalize(b)} #{c}:#{v}"
+
+  defp parse_verse(s) do
+    [_, book, ch, v] = Regex.run(@verse, s)
+    %{book: book, chapter: String.to_integer(ch), verse: String.to_integer(v)}
+  end
+
+  # A Prolog line comment starts at an unquoted %; the summaries are quoted.
+  defp strip_comment(line) do
+    case Regex.run(~r/^((?:[^'%]|'[^']*')*)%/, line) do
+      [_, code] -> code
+      _ -> line
+    end
+  end
+
+  defp verse_in_l1?(%{book: book, chapter: ch, verse: v}) do
+    book in @books and match?({:ok, _}, L1Reader.read_verse(book, ch, v))
+  end
+end

vav_pipeline/test/sugya_test.exs

@@ -0,0 +1,105 @@
+defmodule VavPipeline.SugyaTest do
+  @moduledoc "The case behind each threshold (specs/sugya.md §IV, step 1): the facts are whole, and the Doorpost refuses a rule without them."
+  use ExUnit.Case, async: false
+
+  alias VavPipeline.{Anchors, Doorpost, Sugya}
+
+  test "the sugya file is a Doorpost file, beside the anchors" do
+    assert "talmudic_engine/src/halt/sugya.pl" in Doorpost.files()
+    assert "talmudic_engine/src/halt/anchors.pl" in Doorpost.files()
+  end
+
+  test "every anchored rule has a kind, a precedent and a dissent; every verse is in L1" do
+    assert :ok = Sugya.verify()
+    {:ok, anchors} = Anchors.declared()
+    {:ok, s} = Sugya.declared()
+    for a <- anchors do
+      assert Enum.any?(s.kinds, &(&1.rule == a.rule)), "#{a.rule} has no kind"
+      assert Enum.any?(s.precedents, &(&1.rule == a.rule)), "#{a.rule} has no precedent"
+      assert Enum.any?(s.dissents, &(&1.rule == a.rule)), "#{a.rule} has no dissent"
+    end
+  end
+
+  test "the kinds follow sugya.md §II: marks seen once, the forms as deeds, the grounding rules as words" do
+    {:ok, s} = Sugya.declared()
+    kind = fn r -> Enum.find_value(s.kinds, &(&1.rule == r && &1.kind)) end
+    assert kind.("lo_taaseh_lekha") == "deed"
+    assert kind.("golden_calf") == "word"
+    assert kind.("self_grounding") == "word"
+    assert kind.("even_vaaven") == "measure"
+    for r <- ~w(avodah_zarah shfichut_damim gilui_arayot parah_adumah carrier_centered chelbenah), do: assert(kind.(r) == "mark", r)
+  end
+
+  test "the exception the reader asked to see cited: forged_fringe stands on one witness because it is a mark on the offering" do
+    {:ok, s} = Sugya.declared()
+    e = Enum.find(s.exceptions, &(&1.rule == "lo_taaseh_lekha" and &1.condition =~ "forged_fringe"))
+    assert e, "no single-witness exception for forged_fringe"
+    assert Sugya.cite(e.verse) == "Vayikra 22:20"
+    # and the two-witness dissent is recorded for every form
+    assert Enum.any?(s.dissents, &(&1.rule == "lo_taaseh_lekha" and &1.reading == "single_witness_noted"))
+  end
+
+  test "for_rule/1 renders a rule's sugya for a verdict to carry" do
+    r = Sugya.for_rule("golden_calf")
+    assert r.kind == "word" and r.verse == "Devarim 18:22"
+    assert r.precedent == "tablet(49)"
+    assert Enum.any?(r.dissent, &(&1.reading == "hedged"))
+    assert Enum.any?(r.exception, &(&1.condition == "no_ground_given"))
+    assert Sugya.for_rule("no_such_rule") == nil
+  end
+
+  describe "drift (synthetic spec root)" do
+    setup do
+      temp = Path.join(System.tmp_dir!(), "sugya_test_#{System.unique_integer([:positive])}")
+      for rel <- Doorpost.files() do
+        src = Path.join(Doorpost.repo_root(), rel)
+        dst = Path.join(temp, rel)
+        File.mkdir_p!(Path.dirname(dst))
+        if File.exists?(src), do: File.cp!(src, dst)
+      end
+      on_exit(fn -> File.rm_rf!(temp) end)
+      %{temp: temp, path: Path.join(temp, "talmudic_engine/src/halt/sugya.pl")}
+    end
+
+    test "a mirror verifies", %{temp: temp} do
+      assert :ok = Sugya.verify(temp)
+    end
+
+    test "a rule without a dissent fails: the minority must be recorded", %{temp: temp, path: path} do
+      text = File.read!(path) |> String.replace(~r/^dissent\(even_vaaven,.*\n/m, "")
+      File.write!(path, text)
+      assert {:error, "SUGYA_MISSING: rule even_vaaven has no dissent" <> _} = Sugya.verify(temp)
+    end
+
+    test "a rule without a kind fails", %{temp: temp, path: path} do
+      File.write!(path, String.replace(File.read!(path), "kind(chelbenah,        mark, verse(vayikra, 13, 3)).", ""))
+      assert {:error, "SUGYA_MISSING: rule chelbenah has no kind" <> _} = Sugya.verify(temp)
+    end
+
+    test "a kind that is not one of the four fails", %{temp: temp, path: path} do
+      File.write!(path, String.replace(File.read!(path), "kind(chelbenah,        mark,", "kind(chelbenah,        rumour,"))
+      assert {:error, "SUGYA_INVALID: rule chelbenah has kind rumour" <> _} = Sugya.verify(temp)
+    end
+
+    test "a verse that is not in L1 fails", %{temp: temp, path: path} do
+      File.write!(path, String.replace(File.read!(path), "verse(vayikra, 22, 20)", "verse(vayikra, 22, 99)"))
+      assert {:error, "SUGYA_NOT_IN_L1: Vayikra 22:99" <> _} = Sugya.verify(temp)
+    end
+
+    test "a sugya for a rule that has no anchor fails: nothing added", %{temp: temp, path: path} do
+      File.write!(path, File.read!(path) <> "\nexception(new_rule, whatever, verse(bereishit, 1, 1)).\n")
+      assert {:error, "SUGYA_INVALID: " <> _ = msg} = Sugya.verify(temp)
+      assert msg =~ "new_rule"
+    end
+
+    test "a fact in a comment is not a fact", %{temp: temp, path: path} do
+      File.write!(path, File.read!(path) <> "\n%% kind(imaginary, mark, verse(bereishit, 1, 1)).\n")
+      assert :ok = Sugya.verify(temp)
+    end
+
+    test "a missing sugya file fails", %{temp: temp, path: path} do
+      File.rm!(path)
+      assert {:error, "SUGYA_UNREADABLE: " <> _} = Sugya.verify(temp)
+    end
+  end
+end