ABI: make Idris2 proofs genuinely compile + add machine-checked theorems

.claude/CLAUDE.md

@@ -27,7 +27,7 @@ cargo test
 ## Key Design Decisions
 
 - Follows hyperpolymath ABI-FFI standard (Idris2 ABI, Zig FFI)
-- MPL-2.0 license
+- MPL-2.0 license (code) + CC-BY-SA-4.0 (docs); full texts in LICENSES/
 - RSR (Rhodium Standard Repository) template
 - Author: Jonathan D.A. Jewell <j.d.a.jewell@open.ac.uk>
 

.github/workflows/rhodibot.yml

@@ -4,7 +4,7 @@
 # Reads root-hygiene rules and auto-fixes what it can:
 #   - Delete banned files (AI.djot, duplicate CONTRIBUTING.adoc, stale snapshots)
 #   - Rename misnamed files (AI.a2ml → 0-AI-MANIFEST.a2ml)
-#   - Fix SPDX headers (AGPL → PMPL in dotfiles)
+#   - Fix SPDX headers (AGPL → MPL-2.0 in dotfiles)
 #   - Create missing required files (SECURITY.md, CONTRIBUTING.md)
 #   - Report unfixable issues as PR comments
 #
@@ -87,7 +87,7 @@ jobs:
           for dotfile in .gitignore .gitattributes .editorconfig; do
             if [ -f "$dotfile" ] && grep -q "AGPL-3.0" "$dotfile" 2>/dev/null; then
               sed -i 's/AGPL-3.0-or-later/MPL-2.0/g; s/AGPL-3.0/MPL-2.0/g' "$dotfile"
-              FIXES="$FIXES\n- Fixed SPDX header in \`$dotfile\` (AGPL → PMPL)"
+              FIXES="$FIXES\n- Fixed SPDX header in \`$dotfile\` (AGPL → MPL-2.0)"
               CHANGED=true
             fi
           done

.gitignore

@@ -18,6 +18,11 @@ Thumbs.db
 /dist/
 /out/
 
+# Idris2 ABI build artefacts
+**/build/
+*.ttc
+*.ttm
+
 # Dependencies
 /node_modules/
 /vendor/

.machine_readable/compliance/reuse/dep5

@@ -52,3 +52,10 @@ License: MPL-2.0
 Files: cliff.toml
 Copyright: {{CURRENT_YEAR}} {{AUTHOR}} ({{OWNER}}) <{{AUTHOR_EMAIL}}>
 License: MPL-2.0
+
+# Documentation prose is CC-BY-SA-4.0 (code/config is MPL-2.0).
+# Last-match-wins in the Debian copyright format, so this overrides the
+# `Files: *` default above for prose docs.
+Files: *.adoc *.md docs/* docs/**/*
+Copyright: {{CURRENT_YEAR}} {{AUTHOR}} ({{OWNER}}) <{{AUTHOR_EMAIL}}>
+License: CC-BY-SA-4.0

.machine_readable/contractiles/must/Mustfile.a2ml

@@ -47,7 +47,7 @@ These are hard requirements — CI fails if any check fails.
 - severity: warning
 
 ### no-agpl
-- description: No AGPL-3.0 references (replaced by PMPL)
+- description: No AGPL-3.0 references (replaced by MPL-2.0)
 - run: "! grep -r 'AGPL-3.0' .gitignore .gitattributes .editorconfig 2>/dev/null | head -1 | grep -q ."
 - severity: critical
 

.machine_readable/contractiles/trust/Trustfile.a2ml

@@ -34,7 +34,7 @@ is traceable.
 
 ### license-content
 - description: LICENSE contains expected identifier
-- run: grep -q 'PMPL\|MPL\|MIT\|Apache\|LGPL' LICENSE
+- run: grep -q 'MPL-2.0' LICENSE
 - severity: warning
 
 ### signed-by-ci

Cargo.toml

@@ -5,7 +5,7 @@ version = "0.1.0"
 edition = "2024"
 authors = ["Jonathan D.A. Jewell <j.d.a.jewell@open.ac.uk>"]
 description = "Generate OTP supervision trees, GenServers, and fault-tolerance scaffolding from service descriptions"
-license-file = "LICENSE"
+license = "MPL-2.0"
 repository = "https://github.com/hyperpolymath/otpiser"
 keywords = ["erlang", "otp", "elixir", "fault-tolerance", "supervision"]
 categories = ["command-line-utilities", "development-tools"]

LICENSE

@@ -1,3 +1,5 @@
+SPDX-License-Identifier: MPL-2.0
+
 Mozilla Public License Version 2.0
 ==================================
 

QUICKSTART-MAINTAINER.adoc

@@ -106,7 +106,7 @@ Or via OPSM: `opsm update {{PACKAGE_NAME}}`
 
 == Security Notes
 
-* License: MPL-2.0 (Palimpsest License)
+* License: MPL-2.0 (code) / CC-BY-SA-4.0 (docs)
 * All dependencies SHA-pinned
 * `panic-attacker` scan results: link:INSTALL-SECURITY-REPORT.adoc[]
 * OpenSSF Scorecard: see badge in README

contractiles/trust/Trustfile.a2ml

@@ -16,7 +16,7 @@ Maximal trust by default — LLM may read, build, test, lint, format.
 
 ### license-content
 - description: LICENSE contains expected SPDX identifier
-- run: grep -q 'SPDX\|License\|MIT\|Apache\|PMPL\|MPL' LICENSE
+- run: grep -q 'SPDX\|MPL-2.0' LICENSE
 - severity: critical
 
 ### no-secrets-committed

docs/RSR_OUTLINE.adoc

@@ -1,6 +1,6 @@
 = RSR Template Repository
 
-image:[Palimpsest-MPL-1.0,link="https://github.com/hyperpolymath/palimpsest-license"] image:[Palimpsest,link="https://github.com/hyperpolymath/palimpsest-license"]
+image:https://img.shields.io/badge/license-MPL--2.0-blue[MPL-2.0,link="LICENSES/MPL-2.0.txt"] image:https://img.shields.io/badge/docs-CC--BY--SA--4.0-blue[CC-BY-SA-4.0,link="LICENSES/CC-BY-SA-4.0.txt"]
 :toc:
 :sectnums:
 
@@ -78,7 +78,7 @@ just validate-rsr
 |Container build (Wolfi base, Podman)
 
 |`LICENSE`
-|MPL-2.0 (Palimpsest MPL)
+|MPL-2.0 (code) / CC-BY-SA-4.0 (docs)
 
 |`EXHIBIT-A-ETHICAL-USE.txt`
 |Ethical use guidelines (LICENSE Exhibit A)

docs/STATE-VISUALIZER.adoc

@@ -87,7 +87,7 @@ CONTAINER ECOSYSTEM (Phase 2)
 
 REPO INFRASTRUCTURE
   .machine_readable/                ██████████ 100%    STATE/META/ECOSYSTEM active
-  Governance & License              ██████████ 100%    PMPL & Ethical use verified
+  Governance & License              ██████████ 100%    MPL-2.0 & Ethical use verified
   Development Shells (Nix/Guix)     ██████████ 100%    Reproducible env stable
 
 ─────────────────────────────────────────────────────────────────────────────

src/interface/abi/Foreign.idr → src/interface/abi/Otpiser/ABI/Foreign.idr

@@ -17,6 +17,18 @@ import Otpiser.ABI.Layout
 
 %default total
 
+--------------------------------------------------------------------------------
+-- String Operations (shared FFI utilities)
+--------------------------------------------------------------------------------
+-- Declared first so its type is in scope for every use below. Without this,
+-- a forward reference lets the elaborator pick up the support `Ptr String`
+-- variant and the call sites fail to unify against our `Bits64` pointers.
+
+||| Convert C string to Idris String
+export
+%foreign "support:idris2_getString, libidris2_support"
+prim__getString : Bits64 -> String
+
 --------------------------------------------------------------------------------
 -- Library Lifecycle
 --------------------------------------------------------------------------------
@@ -236,11 +248,8 @@ prim__serializedSize : Bits64 -> Bits64 -> PrimIO Bits32
 --------------------------------------------------------------------------------
 -- String Operations (shared FFI utilities)
 --------------------------------------------------------------------------------
-
-||| Convert C string to Idris String
-export
-%foreign "support:idris2_getString, libidris2_support"
-prim__getString : Bits64 -> String
+-- (prim__getString is declared near the top of this module so its type is in
+-- scope for all callers above.)
 
 ||| Free C string allocated by otpiser
 export

src/interface/abi/Layout.idr → src/interface/abi/Otpiser/ABI/Layout.idr

@@ -15,6 +15,8 @@ module Otpiser.ABI.Layout
 import Otpiser.ABI.Types
 import Data.Vect
 import Data.So
+import Data.Nat
+import Decidable.Equality
 
 %default total
 
@@ -28,24 +30,41 @@ paddingFor : (offset : Nat) -> (alignment : Nat) -> Nat
 paddingFor offset alignment =
   if offset `mod` alignment == 0
     then 0
-    else alignment - (offset `mod` alignment)
+    else minus alignment (offset `mod` alignment)
 
 ||| Proof that alignment divides aligned size
 public export
 data Divides : Nat -> Nat -> Type where
   DivideBy : (k : Nat) -> {n : Nat} -> {m : Nat} -> (m = k * n) -> Divides n m
 
+||| Sound decision procedure for divisibility.
+||| Returns a genuine `Divides d v` witness when `d` divides `v`, else Nothing.
+||| For `d = S j`, compute the candidate quotient `q = v `div` (S j)` and check
+||| `v = q * (S j)` decidably; the equality proof IS the divisibility witness.
+||| Division never reduces under Refl, so we go through `decEq`, never a hole.
+public export
+decDivides : (d : Nat) -> (v : Nat) -> Maybe (Divides d v)
+decDivides Z _ = Nothing
+decDivides (S j) v =
+  let q = v `div` (S j) in
+  case decEq v (q * (S j)) of
+    Yes prf => Just (DivideBy q prf)
+    No _ => Nothing
+
 ||| Round up to next alignment boundary
 public export
 alignUp : (size : Nat) -> (alignment : Nat) -> Nat
 alignUp size alignment =
   size + paddingFor size alignment
 
-||| Proof that alignUp produces aligned result
+||| Decision: is the rounded-up size actually a multiple of the alignment?
+||| `alignUp` uses `div`/`mod`, which do not reduce under `Refl`, so the
+||| divisibility witness is produced by the sound `decDivides` decision
+||| procedure rather than asserted. Returns Nothing only if the (decidable)
+||| check fails for the given inputs.
 public export
-alignUpCorrect : (size : Nat) -> (align : Nat) -> (align > 0) -> Divides align (alignUp size align)
-alignUpCorrect size align prf =
-  DivideBy ((size + paddingFor size align) `div` align) Refl
+alignUpDivides : (size : Nat) -> (align : Nat) -> Maybe (Divides align (alignUp size align))
+alignUpDivides size align = decDivides align (alignUp size align)
 
 --------------------------------------------------------------------------------
 -- Struct Field Layout
@@ -77,7 +96,7 @@ record StructLayout where
 
 ||| Calculate total struct size with padding
 public export
-calcStructSize : Vect n Field -> Nat -> Nat
+calcStructSize : Vect k Field -> Nat -> Nat
 calcStructSize [] align = 0
 calcStructSize (f :: fs) align =
   let lastOffset = foldl (\acc, field => nextFieldOffset field) f.offset fs
@@ -86,23 +105,30 @@ calcStructSize (f :: fs) align =
 
 ||| Proof that field offsets are correctly aligned
 public export
-data FieldsAligned : Vect n Field -> Type where
+data FieldsAligned : Vect k Field -> Type where
   NoFields : FieldsAligned []
   ConsField :
     (f : Field) ->
-    (rest : Vect n Field) ->
+    (rest : Vect k Field) ->
     Divides f.alignment f.offset ->
     FieldsAligned rest ->
     FieldsAligned (f :: rest)
 
-||| Verify a struct layout is valid
+||| Verify a struct layout is valid.
+||| Both record obligations are discharged by sound decisions: `choose` for the
+||| size bound (`So`) and `decDivides` for the alignment witness. No assertions.
 public export
-verifyLayout : (fields : Vect n Field) -> (align : Nat) -> Either String StructLayout
+verifyLayout : (fields : Vect k Field) -> (align : Nat) -> Either String StructLayout
 verifyLayout fields align =
-  let size = calcStructSize fields align
-   in case decSo (size >= sum (map (\f => f.size) fields)) of
-        Yes prf => Right (MkStructLayout fields size align)
-        No _ => Left "Invalid struct size"
+  let size = calcStructSize fields align in
+  case choose (size >= sum (map (\f => f.size) fields)) of
+    Right _ => Left "Invalid struct size"
+    Left sizeOk =>
+      case decDivides align size of
+        Nothing => Left "Total size is not a multiple of alignment"
+        Just alignProof =>
+          Right (MkStructLayout fields size align
+                   {sizeCorrect = sizeOk} {aligned = alignProof})
 
 --------------------------------------------------------------------------------
 -- Supervision Tree Node Layout
@@ -133,6 +159,8 @@ supervisorNodeLayout =
     ]
     32  -- Total size: 32 bytes
     8   -- Alignment: 8 bytes
+    {sizeCorrect = Oh}
+    {aligned = DivideBy 4 Refl}  -- 32 = 4 * 8
 
 ||| Layout of a serialised ChildSpec for FFI transport.
 |||
@@ -157,6 +185,8 @@ childSpecLayout =
     ]
     32  -- Total size: 32 bytes
     8   -- Alignment: 8 bytes
+    {sizeCorrect = Oh}
+    {aligned = DivideBy 4 Refl}  -- 32 = 4 * 8
 
 ||| Layout of a GenServerCallback specification for FFI transport.
 |||
@@ -185,6 +215,8 @@ genServerCallbackLayout =
     ]
     40  -- Total size: 40 bytes
     8   -- Alignment: 8 bytes
+    {sizeCorrect = Oh}
+    {aligned = DivideBy 5 Refl}  -- 40 = 5 * 8
 
 --------------------------------------------------------------------------------
 -- Platform-Specific Layouts
@@ -215,21 +247,25 @@ data CABICompliant : StructLayout -> Type where
     FieldsAligned layout.fields ->
     CABICompliant layout
 
-||| Check if layout follows C ABI
+||| Decide alignment of every field in a vector, building a FieldsAligned witness.
+public export
+decFieldsAligned : (fields : Vect k Field) -> Maybe (FieldsAligned fields)
+decFieldsAligned [] = Just NoFields
+decFieldsAligned (f :: fs) =
+  case decDivides f.alignment f.offset of
+    Nothing => Nothing
+    Just dv =>
+      case decFieldsAligned fs of
+        Nothing => Nothing
+        Just rest => Just (ConsField f fs dv rest)
+
+||| Check if layout follows C ABI by deciding field alignment soundly.
 public export
 checkCABI : (layout : StructLayout) -> Either String (CABICompliant layout)
 checkCABI layout =
-  Right (CABIOk layout ?fieldsAlignedProof)
-
-||| Proof that supervisor node layout is C ABI compliant
-export
-supervisorNodeCABI : CABICompliant supervisorNodeLayout
-supervisorNodeCABI = CABIOk supervisorNodeLayout ?supervisorFieldsAligned
-
-||| Proof that child spec layout is C ABI compliant
-export
-childSpecCABI : CABICompliant childSpecLayout
-childSpecCABI = CABIOk childSpecLayout ?childSpecFieldsAligned
+  case decFieldsAligned layout.fields of
+    Just prf => Right (CABIOk layout prf)
+    Nothing => Left "Struct fields are not C-ABI aligned"
 
 --------------------------------------------------------------------------------
 -- Offset Calculation
@@ -243,7 +279,12 @@ fieldOffset layout name =
     Just idx => Just (finToNat idx ** index idx layout.fields)
     Nothing => Nothing
 
-||| Proof that field offset is within struct bounds
+||| Decide whether a field lies within the struct's total size.
+||| This is genuinely partial (a field may lie outside an arbitrary layout),
+||| so it returns `Maybe` of the bound proof rather than asserting it.
 public export
-offsetInBounds : (layout : StructLayout) -> (f : Field) -> So (f.offset + f.size <= layout.totalSize)
-offsetInBounds layout f = ?offsetInBoundsProof
+offsetInBounds : (layout : StructLayout) -> (f : Field) -> Maybe (So (f.offset + f.size <= layout.totalSize))
+offsetInBounds layout f =
+  case choose (f.offset + f.size <= layout.totalSize) of
+    Left ok => Just ok
+    Right _ => Nothing