Commit Graph
22 Commits
Author SHA1 Message Date
Robert Allan James 346c793ebc proof/: add StarForth_Inference_Words.thy (inference_words.c coverage)
Completes the src/word_source/*.c sweep -- last of the 5 kernel-only
files.

Five INFER-*@ output accessors fully modelled: they read straight from
vm->last_inference_outputs, which is exactly the already-modelled
`last_inference :: inference_outputs_state option` field with matching
per-field names. Q.VARIANCE/INFER-DECAY-SLOPE/INFER-WINDOW-WIDTH get
guard/shape only, capturing a genuine finding: array_ptr sets vm->error
AND the caller still pushes a 0 placeholder regardless, unlike the
"error or push, never both" shape most guarded words in this sweep
follow. L8-UPDATE/L8-TABLE-FORCE get pop-shape only.

Second finding: L8-MODE/L8-UPDATE/L8-APPLY/L8-TABLE-FORCE manipulate
vm->ssm_l8_state (a legacy 16-mode struct) and, per L8-TABLE-FORCE's own
comment, a separate 128-config adaptive table the heartbeat's bandit
actually drives -- NEITHER is the `ssm_l8 :: ssm_l8_state` (4-mode
C0..C3) field this proof suite has modelled since early in the sweep.
Three L8 representations exist in the real system; none of this file's
words touch the one the model tracks. Flagged as an open question, not
guessed at.

WINDOW-DIVERSITY, INFER-RUN, L8-MODE, L8-APPLY, and the six BAYES-*
words deferred (unmodelled subsystems: rolling-window diversity
algorithm, the whole inference-engine run, legacy L8 state, hot-words
cache Bayesian posteriors).

Suite now 53 theories, green.
2026-08-14 16:34:22 -04:00
Robert Allan James 9d178e0efe proof/: add StarForth_Q48_Words.thy (q48_words.c coverage)
17 of 23 words fully modelled (Q.+/-/*//,  Q.ABS/NEG, Q.FROM-INT/TO-INT,
Q.1/0/SCALE, Q.=/</>/0=, Q.MAX/MIN), reusing q48_add/q48_mul/q48_div/
q48_from_u64/q48_to_u64 already in StarForth_Q48_16.thy and cell_abs
(Q.ABS's raw sign-bit test is bit-for-bit cell_abs's `n <s 0`). Added
q48_sub there alongside, the one missing arithmetic primitive.
Q.LOG/EXP/SQRT/SIN/COS deferred (same transcendental-approximation class
already excluded from the sweep at q48_16_words.c). Q.PRINT deferred
(stdout only).

Finding: every word in this file pops/pushes via the VM_POP/VM_PUSH
macros, which resolve to completely unchecked vm_pop_fast/vm_push_fast
when STARFORTH_PERFORMANCE is defined -- a build-flag-gated stack-safety
hazard distinct from (and broader than) the individual missing-guard
instances found elsewhere in the sweep, since it silently disables every
guard in the entire file at once. Modelled assuming the safe path.

Suite now 52 theories, green.
2026-08-14 16:31:39 -04:00
Robert Allan James eb46da65f5 proof/: add lifecycle_words_hosted.c, defer_words.c, log_words.c coverage
StarForth_Lifecycle_Words_Hosted.thy: BIRTH/KILL/PAUSE/RESUME/USE are all
the SAME vm_state transition (pop u, pop caddr, log -- the C's own
"kernel build skips this file via Makefile glob" framing means this
covers only the hosted stand-ins; the real kernel capsule-birth-protocol
words live in src/starkernel/, out of this sweep's scope). First file in
the sweep where every registered word's full vm_state footprint is
captured with no deferred remainder -- name extraction is a pure memory
read, logging is pure I/O. Models the genuine partial-pop-before-error
case (C doesn't check vm->error between its two vm_pop calls).

StarForth_Defer_Words.thy: another duplicate-registration finding, same
class as defining_words.c vs dictionary_manipulation_words.c's [/]/STATE
-- word_registry.c registers this file's DEFER/IS/DEFER@ (Module 27)
AFTER defining_words.c's (Module 17), unconditionally in BOTH builds
(defer_words.c has no __STARKERNEL__ guard despite CLAUDE.md's "kernel-
only addition" framing; the hosted Makefile's SRC wildcard includes it
regardless). This makes StarForth_Defining_Words.thy's DEFER/IS/DEFER@
sentinels describe dead, shadowed code -- corrected in place with
cross-references. The live version hits the same three model gaps
anyway (dictionary-entry creation, data-field addressing, mutable
per-entry dispatch), so only IS's stack-underflow guard is new.

StarForth_Log_Words.thy: the five level-constant pushes, LOG-LEVEL!'s
guard+clamp, and all five LOG-*-STR words fully modelled (the STR words
share lifecycle_words_hosted.c's "pop2 + bounds-check, no vm_state write"
shape). LOG-LEVEL@, the (do-log-N) runtime words (raw threaded-code
pointer, same class as LIT), and the LOG-*" immediates (TIB + compile-
time dependencies) deferred. Finding: LOG-ERROR..DEBUG and LOG-LEVEL@
push with no overflow guard -- more instances of the pattern first found
at DECAY-RATE@.

Suite now 51 theories, green.
2026-08-14 16:24:34 -04:00
Robert Allan James 1e76ebea97 proof/: add console-fabric word coverage (framebuffer/keyboard/scroll/ttf)
Stadium console fabric words (FABRIC.md items 4.3.3/4.3.5/4.3.7e/4.4q/
4.4v/4.4y). All four files gate their real hardware-touching bodies
behind __STARKERNEL__ (and, for keyboard, architecture too):

- StarForth_Framebuffer_Words.thy: PLOT/FB-WIDTH/FB-HEIGHT fully modelled
  for the hosted-build fallback (deterministic, no hardware dependency);
  kernel bodies (fb_put_pixel/fb_width/fb_height) deferred. Finding:
  FB-WIDTH/FB-HEIGHT have no overflow guard before pushing -- second
  instance of this class of bug after DECAY-RATE@.
- StarForth_Keyboard_Words.thy: all 6 words' non-kernel-or-wrong-arch
  fallback modelled (fixed constant pushes / no-op); third and fourth
  missing-overflow-guard instances. Real hardware polling
  (i8042/virtio-input) deferred.
- StarForth_Scroll_Words.thy / StarForth_TTF_Words.thy: both files gate
  registration itself behind __STARKERNEL__, so their words don't exist
  at all in a hosted build -- no fallback to model, sentinel-only.

Suite now 48 theories, confirmed green via a full clean rebuild (HOL-
Library cold-built in 15m18s after an accidental heap clear, StarForth
itself 33s).
2026-08-14 16:15:27 -04:00
Robert Allan James e23900d115 proof/: add StarForth_StarForth_Words.thy (starforth_words.c coverage)
5 of 12 words fully modelled: ENTROPY@/ENTROPY! (XT-pop gap sidestepped
same as ACL words, but note this file's is_valid_dict_entry is a real
membership-check safety improvement over acl_words.c's null-only check),
RESET-ENTROPY (dictionary-wide bulk reset, same technique as
ACL-INIT-PRIMITIVES), ZUSE-AUTHENTICATE (single-field set), VERSION
(identity, no stack effect at all). TOP-WORDS/SEED/RANDOM/WAIT get
guard/shape only -- SEED and RANDOM both depend on g_prng_state, a
file-scope C static shared across the whole Tripod fleet (yet another
instance of the recurring file-scope-static-instead-of-per-VM pattern,
here meaning every VM draws from the same RNG stream). WORD-ENTROPY/(-/
INIT not modelled (pure printf / TIB dependency / real filesystem I/O
plus a custom text parser).

Finding: register_starforth_words registers its 10 words, bootstraps
the STARFORTH vocabulary, then re-registers 12 words (same 10 plus
ENTROPY@/ENTROPY!) into that vocabulary context -- noted as the second
file where registration order matters for which body actually runs,
judgment on intentionality deferred to the largely-unmodelled vocabulary
chain mechanics.

Suite now 44 theories, green.
2026-08-14 15:48:21 -04:00
Robert Allan James 81b1083100 proof/: add physics diagnostic/benchmark/pipelining coverage
StarForth_Physics_Diagnostic_Words.thy (physics_diagnostic_words.c):
3 of 4 words are pure-printf identity transitions; PHYSICS-BURN's guard
modelled, its arbitrary dynamically-selected func-pointer execution loop
is a new class of gap (not reducible to any prior one).

StarForth_Physics_Benchmark_Words.thy (physics_benchmark_words.c):
hot-words cache is a whole unmodelled subsystem. PHYSICS-RESET-STATS's
pipeline_metrics half (3 real vm_state fields) modelled; everything else
in the file deferred.

StarForth_Physics_Pipelining_Diagnostic_Words.thy
(physics_pipelining_diagnostic_words.c): root-cause finding --
`word_transition_metrics` has been a declared record type in
StarForth_Base.thy since early in the sweep but was never wired into
`dict_entry` as a field, so every word in this file touches state with
zero abstract representation. Three no-arg words modelled as identity
(with an explicit caveat that this reflects the model's blind spot, not
a no-op claim about the C); the three lookup words get only their
simplest empty-stack underflow case.

Suite now 43 theories, green.
2026-08-14 15:43:48 -04:00
Robert Allan James 873c537e20 proof/: add StarForth_Physics_Freeze_Words.thy (physics_freeze_words.c coverage)
6 of 9 words fully modelled (FREEZE-WORD, UNFREEZE-WORD, FROZEN?, HEAT!,
HEAT@, DECAY-RATE@), parameterised over an explicit word_id-resolution
input to sidestep the same raw-pointer name-lookup gap already flagged
for FIND -- these words are an even rawer variant (caddr is an
already-computed VM address cast straight to a host pointer, not a
parsed input-stream token). SHOW-HEAT/ALL-HEATS (stdout diagnostics) and
FREEZE-CRITICAL (21-name batch of the same FREEZE-WORD op) deferred.

Finding: DECAY-RATE@ is the only push-only word in this file (and one of
few in the whole sweep) with no data-stack-full guard before the raw
push -- a genuine overflow hazard, modelled faithfully.
2026-08-14 14:54:00 -04:00
Robert Allan James 40758fa554 proof/: add StarForth_Dictionary_Heat_Diagnostic_Words.thy (dictionary_heat_diagnostic_words.c coverage)
4 of 6 words fully modelled (HEAT-PERCENTILES, LOOKUP-STRATEGY@/!,
SHOW-HEAT-OPTIMIZATION); REORG-BUCKETS deferred (bucket/lookup-table
structure has no vm_state counterpart); COMPARE-LOOKUPS partially --
guards and its net-zero effect on lookup_strategy modelled, the timed
FIND-loop benchmarking body deferred (same FIND gap already flagged
elsewhere).
2026-08-14 14:47:24 -04:00
Robert Allan James 770ed26952 proof/: add StarForth_ACL_Words.thy (acl_words.c coverage)
Fills the gap the existing ACL_*.thy policy theories deliberately don't
cover: the six plain field-accessor getters (ACL-MODE@, ACL-PINNED?,
ACL-TTL@, ACL-ALLOW@, ACL-HEAT@, ACL-WORD-ID) and ACL-INIT-PRIMITIVES
(dictionary-wide bulk reset of unpinned entries). The mutating words
(ACL-PIN, ACL-MODE!, ACL-TTL!, ACL-ALLOW!, ACL-INHERIT) were already
modelled word-for-word in ACL_Pin_Monotone.thy / ACL_Inherit_Clears_Pin.thy
and are cross-referenced, not duplicated.

ACL-INIT-PRIMITIVES models cleanly despite the C using a raw ->link
linked-list walk: the abstract word_id-indexed dictionary expresses "for
every entry" directly, without needing the pointer-chasing gap already
flagged for TRAVERSE/FIND elsewhere.
2026-08-14 14:43:55 -04:00
Robert Allan James 4d025ab0f4 proof/: add StarForth_Defining_Words.thy (defining_words.c coverage)
4 of 19 words fully modelled ([, ], STATE, IMMEDIATE), 2 guard-only
partial (:, ;), rest deferred behind three named model gaps: dictionary-
entry creation (never modelled anywhere in this suite before now),
data-field addressing (same class as the existing >BODY gap), and
mutable per-entry dispatch (word_table is a fixed global, can't express
DEFER/IS).

Finding: defining_words.c's [/]/STATE are registered after (and thus
permanently shadow) dictionary_manipulation_words.c's versions of the
same names -- that file's prior "dead cross-VM-shared static" finding
only ever applied to the shadowed, unreachable code. The live versions
correctly use vm->state_addr, a real per-VM field, now added to
vm_state.
2026-08-14 14:33:29 -04:00
Robert Allan James a34fba5c1c proof/: add StarForth_Vocabulary_Words.thy (vocabulary_words.c coverage)
1 of 7 registered words modeled, partially: (FIND)'s two concretely-
decidable failure branches (invalid address; invalid length-derived
range). Its "found" branch, and VOCABULARY/DEFINITIONS/CONTEXT/CURRENT/
FORTH/ORDER entirely, are deferred.

Genuine finding: this is the 7th and by far most severe occurrence of
the file-scope-static-instead-of-per-VM-field bug pattern in this sweep.
The ENTIRE vocabulary subsystem (forth_vocab/context_vocab/current_vocab,
context_var_addr/current_var_addr, the first-character search index) is
file-scope C statics, not struct VM fields. In the Tripod multi-VM
fleet, one VM's VOCABULARY/DEFINITIONS/FORTH silently changes where
every other VM looks up and defines words -- a correctness hazard in
ordinary word resolution for the whole fleet, not just a diagnostic-flag
leak like the smaller prior instances. init_vocabulary_system's `static
int initialized` guard compounds this: only the first VM to touch any
vocabulary word seeds the vocabulary roots, from its own dictionary.
2026-08-14 14:12:30 -04:00
Robert Allan James 283c4780e4 proof/: add StarForth_System_Words.thy (system_words.c coverage)
10 of 16 registered words modeled (COLD/WARM/BYE/WORDS/VLIST/PAGE/NOP/
QUIT/ABORT/EXECUTE guard-shape), plus the internal (ABORT") runtime
helper. Deferred: ( and \ (TIB dependency), SAVE-SYSTEM (real file I/O),
79-STANDARD (reads a non-per-VM global), ABORT" compile-time half (TIB +
codegen), SEE (TIB + raw threaded-code pointer walk).

Two findings. (1) system_running/forth_79_standard are file-scope C
statics doing per-VM-shaped work -- the 5th and 6th occurrence of this
bug pattern in the sweep (previously: control_words.c's cf_stack,
dictionary_manipulation_words.c's state_variable, string_words.c's
word_scratch_addr). (2) EXECUTE casts a popped FORTH cell straight to a
DictEntry host pointer and calls through it (entry->func(vm)), gated
only by a null check -- same hazard class as format_words.c's ?/DUMP but
far more consequential since EXECUTE is a core, ubiquitous primitive
rather than a diagnostic word. Flagged as the highest-severity finding
this sweep has produced.
2026-08-14 14:09:41 -04:00
Robert Allan James cf205ca04a proof/: add StarForth_Editor_Words.thy and StarForth_Format_Words.thy
editor_words.c: zero tractable words (first such file in this sweep) --
every word routes through the same deferred block-window cache as
block_words.c, and EDIT is an interactive stdin/stdout REPL loop, not a
single-step transition.

format_words.c: 17 of 19 registered words modeled (# and #S deferred,
multi-precision division out of scope). Two genuine C findings recorded:
(1) DECIMAL/HEX/OCTAL write only the FORTH-visible memory cell at
base_addr, never the separate vm->base host-mirror field that number
OUTPUT words actually read -- proved formally
(decimal_does_not_change_vm_base et al.), so HEX/OCTAL/DECIMAL silently
never affect printed output, only parsed input. (2) ? and DUMP cast the
popped cell directly to a host pointer and dereference it, bypassing
vm_addr_ok entirely -- an out-of-VM-bounds read, not modeled since it
isn't a vm->memory access at all.

Adds base_addr/hold_addr/hold_pos to vm_state (StarForth_Base.thy),
matching the scr_addr/here pattern from earlier files.
2026-08-14 14:03:05 -04:00
Robert Allan James 16435a4229 proof/: add StarForth_IO_Words.thy (io_words.c coverage)
7 of 9 registered words modeled (EMIT/CR/?TERMINAL/TYPE/SPACE/SPACES/
(do-string)); KEY and ." deferred (real external input / TIB-adjacent
input-buffer dependency, same categories as earlier deferrals in this
sweep). Two genuine C findings recorded: ?TERMINAL is a permanent stub
always returning false, and TYPE's bounds check has a signed-integer-
overflow bypass (addr+count wraps negative for large addr/count,
defeating the VM_MEMORY_SIZE guard) with a machine-checked witness.
2026-08-14 13:55:09 -04:00
Robert Allan JamesandClaude Sonnet 5 c1360df2d1 proof/: add StarForth_Block_Words.thy (SCR only)
block_words.c is categorically different from every file covered so far in
this sweep: every other word_source file operates on pure per-VM internal
state already in vm_state (data_stack/return_stack/memory/dictionary).
block_words.c sits on top of a real disk-backed I/O subsystem
(block_subsystem.h) plus a per-VM in-memory cache of it
(vm->blk_vm_lbn/blk_vm_cbuf/blk_vm_dirty/blk_vm_next), none of which are
in vm_state.

Only SCR is self-contained (just needs vm->scr_addr, added to vm_state
the same way here/ecw_nesting were for earlier files). The other 11 words
are deferred for three reasons documented in the theory header: the
block-window cache subsystem (a modeling project on the scale of the
deferred TIB input subsystem, not a one-word extension), real disk I/O via
block_subsystem.h, and recursive vm_interpret()/printf() in LOAD/LIST/
THRU/-->.

Noted in passing: blk_vm_evict/blk_vm_flush_all's own comments document a
real raw-pointer-lifetime bug (stale C buffer pointers after block-
subsystem struct-copy eviction) that was already found and fixed by hand
in the C, before this suite ever looked at the file -- not an open issue,
just worth recording as prior art for exactly the class of bug this sweep
exists to catch.

30 theory files verify with zero errors.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
2026-08-13 23:14:24 -04:00
Robert Allan JamesandClaude Sonnet 5 fe3169dac9 proof/: add StarForth_String_Words.thy (BL/COUNT/CMOVE/CMOVE>/BLANK/-TRAILING/SCAN/SKIP/COMPARE)
Covers the 9 self-contained words in string_words.c that operate purely on
data_stack/memory with no dependency outside the existing model. Introduces
vm_addr_ok_m, a literal transcription of the real C vm_addr_ok bounds check
(src/vm.c:815-820) using VM_MEMORY_SIZE -- more precise than the sign-only
check earlier memory words used -- and resolve_span, a shared helper for
the auto-detect-counted-string pattern that recurs across six of this
file's words.

16 words deliberately not modeled, in three groups (full reasoning in the
theory header): (a) WORD/SPAN/TIB/>IN/SOURCE/QUERY/EXPECT depend on the
lazily-allocated TIB input subsystem (vm->tib_buf via vm_input_ensure),
which has no vm_state counterpart; QUERY/EXPECT also call fgets(stdin)
directly, real I/O with no HOL formalization; (b) CONVERT/NUMBER/ENCLOSE
depend on raw C-string scanning (strlen past a single vm_addr_ok-checked
byte -- a genuine unbounded-read hazard, noted not chased) or strtol(); (c)
S"/(s")/LITERAL/[LITERAL]/['] depend on the same compile-time/threaded-code
machinery already out of scope from control_words.c. SEARCH is deferred
despite being self-contained -- its nested substring search needs a bigger
proof-engineering lift than the single-pass helpers used here.

Third occurrence of the file-scope-static-instead-of-per-VM-field bug
pattern noted (WORD's word_scratch_addr), matching control_words.c's
cf_stack and dictionary_manipulation_words.c's state_variable -- not fixed,
flagged for aggregation when raised to Bob.

29 theory files verify with zero errors.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
2026-08-13 22:58:18 -04:00
Robert Allan JamesandClaude Sonnet 5 45c381ca6c proof/: add StarForth_Control_Words.thy (runtime branch/loop/EXIT words)
Covers the runtime half of control_words.c fully: (BRANCH), (0BRANCH),
(?DO), (DO), (LOOP), (+LOOP), (LEAVE), UNLOOP, I, J, EXIT. The "vm_ip as
raw pointer" gap flagged at every earlier resume point turns out not to
need a new model extension -- return_stack-held addresses dereference into
vm->memory exactly like @/! addresses from the data stack, so the existing
mem_read/unat machinery from StarForth_Memory_Words covers it directly.

The compile-time half (IF/ELSE/THEN, BEGIN/WHILE/REPEAT/AGAIN/UNTIL, the
compiling halves of ?DO/DO/LOOP/+LOOP/LEAVE, CASE/OF/ENDOF/ENDCASE) is left
unmodelled, not from a model gap but a genuine architectural finding:

Headline finding, not fixed: every compile-time control-flow word operates
on FILE-SCOPE C statics (cf_stack/cf_sp, cf_last_mode, leave_addrs/leave_sp,
endof_addrs/endof_sp, and their mark-stacks) -- none are struct VM fields,
none are keyed by VM instance. In the Tripod multi-VM fleet, two VMs
compiling control structures at overlapping times corrupt each other's
IF/DO/CASE nesting through this shared global state, and a VM whose
compilation aborts mid-structure leaves stale cf_sp/leave_sp/endof_sp state
for whichever VM compiles next. cf_epoch_sync's mode-transition reset
heuristic is itself keyed off a single global (cf_last_mode), not per-VM,
so it can neither reliably detect nor reliably avoid false resets across
VMs. Modelling these words against vm_state would require either inventing
a field the real implementation doesn't have (silently fixing the bug in
the proof) or modelling a bare global with no plumbing precedent in this
suite -- both out of scope, left as documented gaps.

28 theory files verify with zero errors.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
2026-08-13 20:19:50 -04:00
Robert Allan JamesandClaude Sonnet 5 77d8f0606a proof/: add StarForth_Dictionary_Manipulation_Words.thy ([/]/STATE/SMUDGE/HIDDEN/INTERPRET)
Covers the mode/flag half of dictionary_manipulation_words.c that's provable
against the existing vm_mode/dictionary/latest_id model. The raw-pointer
DictEntry navigation half (>BODY/>NAME/NAME>/>LINK/LINK>/CFA/LFA/NFA/PFA/
TRAVERSE/FIND/') is left unmodelled -- same class of gap as control_words.c's
deferred vm_ip/return-stack-as-raw-pointers issue, since the abstract
dict_entry record is word_id-indexed, not addressed, and has no counterpart
for struct-relative pointer arithmetic (name_len, link, body offset).

Genuine findings recorded in comments, not fixed:
- [, ], STATE, and INTERPRET all read/write a file-scope `static cell_t
  state_variable` -- NOT vm->state_var, the real per-VM STATE field used
  everywhere else in the interpreter. In the Tripod multi-VM fleet this
  static is shared across every VM instance, not per-VM.
- dictionary_m_word_hidden's dead #else branch (unreachable since
  WORD_HIDDEN is always defined) calls a function that doesn't exist
  (dictionary_word_smudge vs. the real static dictionary_m_word_smudge).

27 theory files verify with zero errors.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
2026-08-13 19:33:42 -04:00
Robert Allan JamesandClaude Sonnet 5 92474c5219 proof/: add StarForth_Dictionary_Words.thy (HERE/ALIGN/ALLOT/,/C,/2,/PAD/LATEST)
Adds VM_MEMORY_SIZE and DICTIONARY_MEMORY_SIZE constants to StarForth_Base.thy
(previously only STACK_SIZE existed). SP@/SP! left unmodelled (oops-flagged
with explanation) -- the list-based data_stack model has no independent dsp
register distinct from list length, which is exactly what SP! manipulates.

Genuine findings recorded in comments, not fixed:
- LATEST has an identical body to HERE (both just push vm->here) rather than
  consulting vm->latest -- doesn't return what its own doc comment claims.
- ALIGN (via vm_align/vm_allot) bounds-checks here against
  DICTIONARY_MEMORY_SIZE (2MB), while ALLOT/,/C,/2, bound-check directly
  against VM_MEMORY_SIZE (5MB) instead -- two different ceilings for the
  same dictionary pointer.

Full suite (26 theory files) verifies with zero errors.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
2026-08-13 18:12:54 -04:00
Robert Allan JamesandClaude Sonnet 5 d0fcd2ed86 proof/: add StarForth_Mixed_Arithmetic_Words.thy (M+/M-/MOD//MOD/*//*/MOD)
Covers word_source/mixed_arithmetic_words.c. Two genuine findings recorded
in comments rather than fixed:

- register_mixed_arithmetic_words registers MOD and /MOD a second time,
  after arithmetic_words.c's own registrations; vm_create_word links new
  entries at the head of vm->latest and FIND scans from vm->latest forward,
  so arithmetic_words.c's MOD/​/MOD are permanently shadowed, unreachable
  dead code once bootstrap completes (verified against
  dictionary_management.c and the module order in word_registry.c).

- M*, M/MOD, and the "avoids intermediate overflow" claim on */ and */MOD
  are false on 64-bit builds: cell_t and "long long" are the same width
  there, so the long-long intermediate does not actually widen the
  product -- it wraps mod 2^64 like plain cell multiplication before the
  32-bit-style split/reconstruction runs. M*/M/MOD are left undefined
  here (oops-equivalent: documented as not modelled, since formalizing
  "the wrong thing, faithfully" adds no proof value) rather than fixed.

MOD/​/MOD/*//*/MOD reuse cell_sdiv/cell_smod from the arithmetic-words
migration; M+/M- transcribe the C's hand-rolled signed carry/borrow
detection literally, proving only stack-level plumbing (not double-
precision correctness, which needs an interpretation function this
suite doesn't build).

All 24 theory files verify with zero errors.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
2026-08-13 13:42:41 -04:00
Robert Allan James 9b4bbc9de6 proof/: add StarForth_Double_Words.thy (2DROP/2DUP/2SWAP/2OVER/2ROT)
Covers the pure double-cell data-stack shuffle words from
src/word_source/double_words.c. Deliberately scoped to exclude:

- 2>R/2R>/2R@: branch on vm->ecw_nesting, a field vm_state doesn't track
  at all -- needs a model extension first, not attempted here.
- S>D/D+/D-/DNEGATE/DABS/DMAX/DMIN/D</D=/D0=/D0</D2*/D2/: depend on
  cell_t being a fixed-width (64-bit) wrapping integer (explicit
  unsigned-long carry/borrow arithmetic, bitwise complement with
  wraparound). StarForth_Base.thy's "cell = int" is unbounded, not
  fixed-width, so this isn't expressible as currently modeled. Fixing it
  means deciding whether cell becomes a 64-bit word type everywhere
  (ripples into all 23 already-verified theories) -- a foundational
  decision, flagged for later, not made as a side effect of this file.

24 theory files now verify with zero errors.
2026-08-13 12:49:02 -04:00
Robert Allan James a5ed8c3d87 Initial commit — LithosAnanke kernel 2026-08-01 07:49:56 -04:00