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+# WO80 — A4 stage 1: the ISC semantic rulings inventory
+
+Status: **IN PROGRESS** (inventory seeded 2026-10-21; each point needs
+its empirical ruling + test vector)
+The IS-1 spec document (A4's vehicle, WO74 dependency) is authored from
+this inventory: every point gets (a) the grammar anchor, (b) the ruby
+interpreter's actual behavior verified by a test, (c) a normative
+ruling.
+
+## The semantic surface (code anchors: interscript-ruby @ main)
+
+| # | area | grammar anchor | interpreter anchor |
+|---|------|----------------|--------------------|
+| 1 | stage composition | grammar/concerns/stages.rb (sequence_block, parallel_block, run_rule, separate_directive) | interpreter.rb `execute_rule` / `call` |
+| 2 | parallel rule priority + `separator` | stages.rb:45-53 | the parallel executor pass |
+| 3 | run (stage composition across dependencies) | stages.rb:120 | dependency-aliased dispatch |
+| 4 | funcall (`rababa` + kwargs passthrough) | stages.rb:70-77 | stdlib adapters (optional layer) |
+| 5 | item algebra: any / character classes / ranges / alternation | grammar/concerns/primitives.rb (21 rules) | `build_item` |
+| 6 | maybe + capture + ref composition | grammar/concerns/items.rb (21 rules) | `build_item`/capture frame |
+| 7 | boundary / word guards + casing interaction | primitives.rb + interpreter case handling | `build_regexp` + case pass |
+| 8 | aliases (local/remote/imported) + dependency resolution | grammar/concerns/aliases.rb, dependencies.rb | registry alias resolution |
+| 9 | metadata contract + embedded tests | grammar/concerns/metadata.rb, tests.rb | test runner |
+| 10 | charset/casing directives (`upcase`/`downcase`/`title` stdlib) | metadata/system concerns | stdlib functions |
+
+## Method per point
+1. Write the empirical test against the ruby interpreter (the reference
+   runtime).
+2. Run the same vector through ts + py (the C1 harness).
+3. Divergence = an open ruling -> decide, encode the ruling as a
+   normative spec section + a frozen vector.
+4. IS-1 v2 text accumulates one section per ruled point; the document
+   ships when all 10 close (then D2 releases it).