Two clause shapes the code had already named

.claude/skills/ci-gates/SKILL.md

@@ -5913,3 +5913,48 @@ assertions now actually run.
 **Do not read that column falling as damage without opening each spec.** One was
 a real false property, two were shape complaints, and five other specs went the
 other way once the backend defects they exposed were fixed (cc 158 → 163).
+
+## 173. The code often names the shape it fails on — grep your own comments
+
+Two rungs this pass were shapes the parser had already described in prose and
+never handled:
+
+    // it can also mean we stopped mid-clause -- e.g. on the comma of
+    // `given clk = true, rst_n = false`
+
+That comment sits at the top of the loop that then discards exactly that. 19
+fallback events in one spec. The other, `given crossings: [i32] = []`, is the
+same story one arm down.
+
+Together with the `fn name() given …` arm from an earlier pass and the `forall`
+arm, that is **four** defects in one file where somebody understood the shape
+well enough to write it down and stopped short of lowering it.
+
+**A comment naming a construct next to a `skip`, a `return`, or a fallback is a
+scoped-and-abandoned fix.** It is a better-signposted target than any census,
+and `grep` finds it in seconds.
+
+## 174. "Someone who knows the domain" was me, one script later
+
+I filed a failing assertion saying it needed *"someone who knows the intended
+encoding"*. Both functions were in the same file. Transcribing them to twelve
+lines of Python answered it completely: the encoder is balanced ternary, the
+decoder is unipolar, they are not inverses, and 8 of 16 values fail.
+
+It also found a second bug the first one hid — with the correct inverse, three
+balanced trits span −13..13, so the test's `i < 16` bound walks past the
+encodable range regardless.
+
+**Before deferring a question to a human, check whether the artefact answers
+it.** Deferring is right when the question is a *decision* (which encoding is
+intended — still open). It was wrong for the part that was arithmetic.
+
+## 175. A census that names a target you cannot open stops one step short
+
+`--fallbacks` reported *19 events in 1 spec* and could not say which spec. I
+brute-forced it by looping the whole corpus through a per-file command.
+
+The fix was ten lines: let the census take `--show <spec>` and scope to one file.
+**Any aggregate you build should have a per-item mode from the start** — you will
+need it the first time the aggregate says something interesting, which is
+immediately.

.trinity/seals/ISAMemoryOps.json

@@ -1,8 +1,8 @@
 {
-  "gen_hash_c": "sha256:67a78d90bb7cb889f3e6c037fdcba78b75f7f419c191a3afa519a844a02c24b5",
+  "gen_hash_c": "sha256:f774cae150e65db765a73b61432e809285899aec07634c5b582ef73400b2721b",
   "gen_hash_rust": "sha256:08c0a5537152d0d7f2eae51a2a8b78932821460d3d6cf6d61d376570235db239",
   "gen_hash_verilog": "sha256:0dccef9c3c538ea2399276395a58aaa116f002a42e4180c75d46756cb9f56e0b",
-  "gen_hash_zig": "sha256:1d2982e1cbc4e526ff2ff1d64481c96a956ac9abffabd6b292b4a6d4a623d76b",
+  "gen_hash_zig": "sha256:4c2cc4e686186bdd7bd495cd473f11fbba6c71820488fd68cf9f49955183dc3b",
   "module": "ISAMemoryOps",
   "ring": 12,
   "sealed_at": "2026-08-28T00:21:37Z",

.trinity/seals/JonesPolynomial.json

@@ -1,8 +1,8 @@
 {
-  "gen_hash_c": "sha256:f35215644bc1fb1fac23407da26ff08b4e562f0a0cb5218fe773451a401f6df1",
+  "gen_hash_c": "sha256:c286be618ed78366c1df1dd44cb15c1e6fd57fa37bf557b03be11b0bb8f854af",
   "gen_hash_rust": "sha256:2dd52a6bc47b88e5ea49fff38bbe9937fa3b3e87e8d104e6314091c94d3e1d3f",
   "gen_hash_verilog": "sha256:644d8c5309231400b435250fd966219bd5b5b28c9ae8732a5a48884088072fa0",
-  "gen_hash_zig": "sha256:d8f4fb82c1461dc3a500e0e895bb8a4b196fb33b1d3e0136834b8fdaf535b76a",
+  "gen_hash_zig": "sha256:1c78dfad02821454197755756ccc61755626a4f901350aa8be5c14395c06fef3",
   "module": "JonesPolynomial",
   "ring": 12,
   "sealed_at": "2026-08-28T00:21:37Z",

.trinity/seals/TernaryControlFlow.json

@@ -1,8 +1,8 @@
 {
-  "gen_hash_c": "sha256:04fe0bc679daacc52a3601b2a337fc098780585ec0944e8802706bf277f3df05",
+  "gen_hash_c": "sha256:d042f8bfaaef6bd86b05d080a61c1fd89f196b8bb1d7ef58aa1069dfea7bbe8f",
   "gen_hash_rust": "sha256:0b6a37615eadf1a45b07eaeb4f7dcad3e209605e93a695287bf0ca414c25bbbe",
   "gen_hash_verilog": "sha256:c4e7373882bf56f5fc546a7d03ee7de41e6fa7b4a91b87cbe8fc03be6ba5604e",
-  "gen_hash_zig": "sha256:51ff256df040056f4e700416f2b25a9ceb3bb150b0e06c0df7e4219eed408c28",
+  "gen_hash_zig": "sha256:b8c7be6f8bd788eb6fa8642a2dcc7d76ce34a7e1003d6dce4626a0f1e65b897b",
   "module": "TernaryControlFlow",
   "ring": 12,
   "sealed_at": "2026-08-28T00:21:37Z",

.trinity/seals/isa_ISAMemoryOps.json

@@ -1,11 +1,11 @@
 {
-  "gen_hash_c": "sha256:67a78d90bb7cb889f3e6c037fdcba78b75f7f419c191a3afa519a844a02c24b5",
+  "gen_hash_c": "sha256:f774cae150e65db765a73b61432e809285899aec07634c5b582ef73400b2721b",
   "gen_hash_rust": "sha256:08c0a5537152d0d7f2eae51a2a8b78932821460d3d6cf6d61d376570235db239",
   "gen_hash_verilog": "sha256:0dccef9c3c538ea2399276395a58aaa116f002a42e4180c75d46756cb9f56e0b",
-  "gen_hash_zig": "sha256:1d2982e1cbc4e526ff2ff1d64481c96a956ac9abffabd6b292b4a6d4a623d76b",
+  "gen_hash_zig": "sha256:4c2cc4e686186bdd7bd495cd473f11fbba6c71820488fd68cf9f49955183dc3b",
   "module": "ISAMemoryOps",
   "ring": 12,
-  "sealed_at": "2026-08-29T04:11:28Z",
+  "sealed_at": "2026-08-29T04:46:46Z",
   "sealed_by": "t27c-bootstrap@0.2.0",
   "spec_hash": "sha256:29ad72599016b8ced9266c0cce3604e11222c3e7d569768312df89903088cff3",
   "spec_path": "specs/isa/ternary_memory.t27"

.trinity/seals/isa_TernaryControlFlow.json

@@ -1,11 +1,11 @@
 {
-  "gen_hash_c": "sha256:04fe0bc679daacc52a3601b2a337fc098780585ec0944e8802706bf277f3df05",
+  "gen_hash_c": "sha256:d042f8bfaaef6bd86b05d080a61c1fd89f196b8bb1d7ef58aa1069dfea7bbe8f",
   "gen_hash_rust": "sha256:0b6a37615eadf1a45b07eaeb4f7dcad3e209605e93a695287bf0ca414c25bbbe",
   "gen_hash_verilog": "sha256:c4e7373882bf56f5fc546a7d03ee7de41e6fa7b4a91b87cbe8fc03be6ba5604e",
-  "gen_hash_zig": "sha256:51ff256df040056f4e700416f2b25a9ceb3bb150b0e06c0df7e4219eed408c28",
+  "gen_hash_zig": "sha256:b8c7be6f8bd788eb6fa8642a2dcc7d76ce34a7e1003d6dce4626a0f1e65b897b",
   "module": "TernaryControlFlow",
   "ring": 12,
-  "sealed_at": "2026-08-29T04:11:28Z",
+  "sealed_at": "2026-08-29T04:46:46Z",
   "sealed_by": "t27c-bootstrap@0.2.0",
   "spec_hash": "sha256:dcb5de4bdcaaac334bf386d0ee8c2badc68a3debababb033eb4a6df16ff6d6ad",
   "spec_path": "specs/isa/ternary_control_flow.t27"

.trinity/seals/race_igla-race-cordic-top.json

@@ -1,11 +1,11 @@
 {
-  "gen_hash_c": "sha256:e61cc48184e5754d9544ae52a3c8ed5dec066333639c883bc5463b29759cb46a",
+  "gen_hash_c": "sha256:ef4f41400ff2f064d61513da02965b70373c2a9df16238155299ca1e726fd161",
   "gen_hash_rust": "sha256:c643445e277d654e432068eea6e9958ccc45b6e394603376c38e3791e8d7c097",
   "gen_hash_verilog": "sha256:4cbfacb005043739944c0fa4ca55fe2f648875c771cb94a9c35e338b9e5eb610",
-  "gen_hash_zig": "sha256:031aa59dda7f6804f13883a661052427ffd3eee7b8d64c7dd89728d8201823d7",
+  "gen_hash_zig": "sha256:5afe1ae2b906f855f5cbddf6337351d42c81132d32851f36ffa2c74791a8dd23",
   "module": "igla-race-cordic-top",
   "ring": 12,
-  "sealed_at": "2026-08-29T01:19:56Z",
+  "sealed_at": "2026-08-29T04:46:46Z",
   "sealed_by": "t27c-bootstrap@0.2.0",
   "spec_hash": "sha256:ef4e2d3e90d9a3b29abb9254cd70e3dd011a566eb73155b4efb7fa340a7db6b8",
   "spec_path": "specs/igla/race/cordic_top.t27"

.trinity/seals/vsa_JonesPolynomial.json

@@ -1,11 +1,11 @@
 {
-  "gen_hash_c": "sha256:f35215644bc1fb1fac23407da26ff08b4e562f0a0cb5218fe773451a401f6df1",
+  "gen_hash_c": "sha256:c286be618ed78366c1df1dd44cb15c1e6fd57fa37bf557b03be11b0bb8f854af",
   "gen_hash_rust": "sha256:2dd52a6bc47b88e5ea49fff38bbe9937fa3b3e87e8d104e6314091c94d3e1d3f",
   "gen_hash_verilog": "sha256:644d8c5309231400b435250fd966219bd5b5b28c9ae8732a5a48884088072fa0",
-  "gen_hash_zig": "sha256:d8f4fb82c1461dc3a500e0e895bb8a4b196fb33b1d3e0136834b8fdaf535b76a",
+  "gen_hash_zig": "sha256:1c78dfad02821454197755756ccc61755626a4f901350aa8be5c14395c06fef3",
   "module": "JonesPolynomial",
   "ring": 12,
-  "sealed_at": "2026-08-28T23:38:44Z",
+  "sealed_at": "2026-08-29T04:46:46Z",
   "sealed_by": "t27c-bootstrap@0.2.0",
   "spec_hash": "sha256:b1ff39e967bed28b4fd7033a0368f00b9a8b395d16dc4d7b62759e27feab3834",
   "spec_path": "specs/vsa/jones_polynomial.t27"

bootstrap/src/compiler.rs

@@ -6396,6 +6396,29 @@ impl Parser {
                     let bind_look = self.save_state();
                     let name = self.current.lexeme.clone();
                     self.advance();
+                    // W699 rung 11: a TYPED binding.
+                    //
+                    //     given crossings: [i32] = []
+                    //
+                    // The arm below peeks for `=` immediately after the name, so
+                    // an annotation between them read as "not a binding" and the
+                    // clause -- and its whole block -- went to the discard. 17
+                    // fallback events across 4 specs, all of them `given`.
+                    //
+                    // The type is parsed and kept on the declaration, the way
+                    // `var x : T = v` already does in the statement arm. If no `=`
+                    // follows the annotation this restores and changes nothing.
+                    let mut typed = String::new();
+                    if self.current.kind == TokenKind::Colon {
+                        let ty_look = self.save_state();
+                        self.advance(); // :
+                        let ty = self.parse_type_annotation();
+                        if self.current.kind == TokenKind::Equals && !ty.is_empty() {
+                            typed = ty;
+                        } else {
+                            self.restore_state(ty_look);
+                        }
+                    }
                     if self.current.kind != TokenKind::Equals {
                         self.restore_state(bind_look);
                         // W906 (0013): a DOTTED/INDEXED LVALUE step --
@@ -6496,7 +6519,55 @@ impl Parser {
                                     }
                                     decl.extra_field = tail;
                                 }
+                                decl.extra_type = typed.clone();
                                 block.children.push(decl);
+                                // W699 rung 10: COMMA-SEPARATED bindings in one
+                                // clause.
+                                //
+                                //     given clk = true, rst_n = false, angle = 4096
+                                //
+                                // The loop's own comment at the top of this
+                                // function names the shape -- "it can also mean we
+                                // stopped mid-clause -- e.g. on the comma of
+                                // `given clk = true, rst_n = false`" -- and nothing
+                                // ever acted on it. 19 fallback events in
+                                // specs/igla/race/cordic_top.t27 alone, each one
+                                // taking a whole block of clauses with it.
+                                //
+                                // Same line only: a comma opening the next line is
+                                // somebody else's punctuation. Anything this cannot
+                                // read restores to the comma and leaves the clause
+                                // as it stands, so a partial list still lowers what
+                                // it understood.
+                                while self.current.kind == TokenKind::Comma
+                                    && self.current.line == self.last_line
+                                    && self.peek.kind == TokenKind::Ident
+                                {
+                                    let cm = self.save_state();
+                                    self.advance(); // ,
+                                    let n2 = self.current.lexeme.clone();
+                                    self.advance(); // name
+                                    if self.current.kind != TokenKind::Equals {
+                                        self.restore_state(cm);
+                                        break;
+                                    }
+                                    self.advance(); // =
+                                    self.in_bdd_clause_value = true;
+                                    let r2 = self.parse_expr();
+                                    self.in_bdd_clause_value = false;
+                                    match r2 {
+                                        Ok(e2) => {
+                                            let mut d2 = Node::new(NodeKind::StmtLocal);
+                                            d2.name = n2;
+                                            d2.children.push(e2);
+                                            block.children.push(d2);
+                                        }
+                                        Err(_) => {
+                                            self.restore_state(cm);
+                                            break;
+                                        }
+                                    }
+                                }
                                 true
                             }
                             Err(_) => false,

bootstrap/src/main.rs

@@ -3992,6 +3992,29 @@ fn run_parse_complete(
     if let Some(path) = bisect {
         return run_bisect(path);
     }
+    // W699: `--fallbacks --show <spec>` scopes the census to one file.
+        //
+        // The corpus view says a shape exists 19 times in 1 spec and cannot say
+        // WHICH -- and a census that names a target you then cannot open is an
+        // instrument that stops one step short.
+        if let Some(path) = show {
+            let src = std::fs::read_to_string(path)?;
+            let events = compiler::Compiler::parse_ast_bdd_fallbacks(&src)
+                .map_err(|e| anyhow::anyhow!("{} does not parse: {}", path, e))?;
+            if events.is_empty() {
+                println!("{}: no whole-block fallback", path);
+                return Ok(());
+            }
+            let lines: Vec<&str> = src.lines().collect();
+            println!("{}: {} whole-block fallback(s)", path, events.len());
+            println!();
+            for (line, why, clause) in &events {
+                let text = lines.get((*line as usize).saturating_sub(1)).unwrap_or(&"");
+                println!("  {:5}| {}", line, text.trim_end());
+                println!("        {why} (on `{clause}`)");
+            }
+            return Ok(());
+        }
     // W634: single-file mode -- print what was discarded, grouped by line, so a
     // human can decide whether any of it is content a theorem depends on.
     if let Some(path) = show {

bootstrap/src/parse_conform.rs

@@ -247,6 +247,22 @@ version of this is the parse-no-discard suite phase.",
         discards: Some(0),
         note: "`for` and `while` are keywords, so they are neither a clause head nor a block boundary and the loop fell through to the whole-block fallback -- taking the assertion after it. 110 fallback events across ~25 specs, the largest non-`forall` shape in the distribution",
     },
+    Case {
+        name: "one_clause_may_bind_several_names",
+        input: "module m\n\n    test t\n        given clk = true, rst_n = false, angle = 4096\n        then clk == true\n",
+        verdict: Verdict::Full,
+        decls: Some(1),
+        discards: Some(0),
+        note: "the loop's own comment named this shape -- `given clk = true, rst_n = false` -- as the reason a block can stop mid-clause, and nothing acted on it. 19 fallback events in one spec, each taking a whole block of clauses with it",
+    },
+    Case {
+        name: "a_clause_binding_may_carry_a_type",
+        input: "module m\n\n    test t\n        given crossings : [i32] = [1]\n        then crossings[0] == 1\n",
+        verdict: Verdict::Full,
+        decls: Some(1),
+        discards: Some(0),
+        note: "the binding arm peeked for `=` immediately after the name, so an annotation between them read as `not a binding` and the whole block went to the discard",
+    },
     Case {
         name: "unterminated_fn_body",
         input: "module m\n\nfn a() -> u32 { return 1;\n",

bootstrap/stage0/FROZEN_HASH

@@ -1 +1 @@
-03cdabb2b2439bb0d3308c94eeecccfad17e45d954659a9612b368900109dff2
+347e84842d907365acafa9edcd4384f1d2d202e381d0babaafb272a690f46d51

docs/now/2026-08-29-the-long-tail-and-two-shapes-the-code-had-already-named.md

@@ -0,0 +1,8 @@
+# NOW -- The long tail, and two shapes the code had already named (2026-08-29)
+
+## The long tail, and two shapes the code had already named (Refs #2754)
+
+- given clk = true, rst_n = false: the loop's own comment names comma-separated bindings as a reason to stop mid-clause, and nothing acted on it -- 19 events in one spec
+- given crossings : [i32] = []: the arm peeked for = immediately after the name, so an annotation between them read as not-a-binding
+- 25093 -> 23926 tokens, 77 -> 76 specs, and not one acceptance column moved: zero rows differ across 650 specs
+- --fallbacks --show <spec> scopes the census to one file; a census that names a target you cannot then open stops one step short

docs/reports/suite_expectations.json

@@ -1,7 +1,7 @@
 {
   "schema_version": 1,
   "generated_by": "t27c suite --bless-expectations",
-  "max_entries": 168,
+  "max_entries": 167,
   "entries": [
     {
       "path": "specs/account/repo.t27",
@@ -612,9 +612,9 @@
       "reason": "top-level drop-recovery discards tokens; parser reaches EOF so `parse` reports success (T42)",
       "issue": 1959,
       "expires": "2026-11-30",
-      "discard_tokens": 1238,
+      "discard_tokens": 499,
       "discard_by_channel": {
-        "bdd-block-fallback": 1237,
+        "bdd-block-fallback": 498,
         "stray-brace": 1
       }
     },
@@ -835,17 +835,6 @@
         "brace-body/in-fallback": 21
       }
     },
-    {
-      "path": "specs/isa/ternary_control_flow.t27",
-      "phase": "parse-no-discard",
-      "reason": "top-level drop-recovery discards tokens; parser reaches EOF so `parse` reports success (T42)",
-      "issue": 1959,
-      "expires": "2026-11-30",
-      "discard_tokens": 30,
-      "discard_by_channel": {
-        "bdd-block-fallback": 30
-      }
-    },
     {
       "path": "specs/isa/ternary_encoding.t27",
       "phase": "parse",
@@ -871,10 +860,10 @@
       "reason": "top-level drop-recovery discards tokens; parser reaches EOF so `parse` reports success (T42)",
       "issue": 1959,
       "expires": "2026-11-30",
-      "discard_tokens": 211,
+      "discard_tokens": 46,
       "discard_by_channel": {
-        "bdd-block-fallback": 128,
-        "brace-body/in-fallback": 83
+        "bdd-block-fallback": 12,
+        "brace-body/in-fallback": 34
       }
     },
     {
@@ -1525,9 +1514,9 @@
       "reason": "parser reaches EOF but DISCARDS top-level tokens (forall-quantified properties)",
       "issue": 2474,
       "expires": "2026-11-30",
-      "discard_tokens": 302,
+      "discard_tokens": 69,
       "discard_by_channel": {
-        "bdd-block-fallback": 289,
+        "bdd-block-fallback": 56,
         "brace-body/in-fallback": 4,
         "top-level-resync": 9
       }