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1aca77d55ccfc7e09a2b973fdb9bdda0630b560f
LithosAnanake/proof/StarForth_Defining_Words.thy
T
Robert Allan JamesandClaude Sonnet 5 1aca77d55c proof/: model the TIB name-parse primitive, close it into CONSTANT's full model 
input_buffer/input_length/input_pos (include/vm.h:415-417) turned out to
be plain per-VM array/scalar fields, not host pointers -- unlike almost
every other input-adjacent gap in this suite. vm_parse_word (src/vm.c:
137-160) is a pure whitespace-delimited scan over them, now modelled as
forth_parse_word in StarForth_Base.thy (is_ws + dropWhile/takeWhile,
faithful to the C's skip-then-copy-with-truncation loop, including that
input_pos only advances past a truncated token by what was actually
copied, matching the C's `len < max_len - 1` bound exactly).

dict_insert_entry (added last session) now takes the entry's name as a
parameter instead of hardcoding the empty string. forth_constant_full
composes forth_parse_word with dict_insert_entry end-to-end as a worked
example: CONSTANT's real order (stack-underflow guard -> pop value ->
parse name -> vm_create_word) is modelled in full up to the data-field
write, which remains the one still-open gap. The other four entry-half
definitions (:/CREATE/VARIABLE/DEFER) take the parsed name as a caller
parameter for now rather than repeating the same composition four more
times in one pass.

Full suite (54 theories) verifies green.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
2026-08-14 22:53:11 -04:00

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theory StarForth_Defining_Words
imports StarForth_Base StarForth_Memory_Words ACL_Pin_Monotone
begin
(* =========================================================================
Mirrors: src/word_source/defining_words.c
Registers: : ; CREATE VARIABLE CONSTANT IMMEDIATE STATE [ ] FORGET
COMPILE [COMPILE] LIT LITERAL does_rt DOES> DEFER IS DEFER@
── Duplicate-registration finding (corrects a StarForth_Dictionary_
Manipulation_Words.thy note) ────────────────────────────────────────
`src/word_registry.c` registers dictionary_manipulation_words.c's `[`,
`]`, `STATE` (Module 13, line 122) BEFORE defining_words.c's `[`, `]`,
`STATE` (Module 17, line 126). FORTH dictionary lookup finds the MOST
RECENT definition of a name first, so defining_words.c's versions are
the only ones ever reachable -- dictionary_manipulation_words.c's `[`/
`]`/`STATE` are permanently shadowed, dead code from the moment boot
registration completes. CORRECTED 2026-08-14: `INTERPRET` is NOT part of
this shadow -- defining_words.c never registers a word named INTERPRET
at all (confirmed by grep), so dictionary_manipulation_words.c's
INTERPRET is the only registration that exists and is live, not dead.
The earlier version of this note (and proof/FINDINGS.md) incorrectly
folded it into the shadowed group.
This also CORRECTS that file's finding, not just supersedes it: its
`[`/`]`/`STATE` write/read a dead file-scope `static cell_t
state_variable`, cross-VM-shared and never the real per-VM STATE. The
LIVE versions here (defining_word_left_bracket/right_bracket/state) use
`vm->state_addr` (include/vm.h:452) -- a genuine per-VM VM-memory
address, correctly written via `vm_store_cell`. The dead-static bug is
real IN THE SHADOWED CODE, but does not reach runtime: no VM instance's
`[`/`]`/`STATE` actually touches that static. Added `state_addr :: nat`
to vm_state (StarForth_Base.thy) to model this correctly.
── Scope of this file ──────────────────────────────────────────────────
Split three ways:
1. Mode/flag/address words ([, ], STATE, IMMEDIATE) -- fully modelled,
provable against `vm_mode`/`state_addr`/`memory`/`dictionary`/
`latest_id`.
2. `:` / `;` -- guard conditions modelled; `:`'s STATE/mode-setting half
of `vm_enter_compile_mode` is modelled (identical shape to `]`), AND
(added 2026-08-14, see `dict_insert_entry` below) its dictionary-
entry-creation half is now PARTIALLY modelled too
(`forth_colon_entry_half`: fresh word_id, WORD_SMUDGED flag, ACL
defaults) -- what remains unmodelled is named at that definition's
site. `;`'s entire effect beyond the guard (`vm_exit_compile_mode`:
find/compile EXIT, clear WORD_SMUDGED, set WORD_COMPILED, evict
hot-words cache) is still NOT modelled, for the same reason plus
dependence on the hot-words cache, itself never modelled in this
suite.
3. Everything else (CREATE, VARIABLE, CONSTANT partially modelled as of
2026-08-14, see below; FORGET, COMPILE, [COMPILE], LIT, LITERAL,
does_rt, DOES>, DEFER, IS, DEFER@, and the three defining-runtime
functions CREATE/VARIABLE/CONSTANT install still NOT modelled) --
each hits one or more of the same three model gaps, named once here
rather than repeated per word:
(a) DICTIONARY-ENTRY CREATION, PARTIALLY CLOSED 2026-08-14. Was not
modelled anywhere in this proof suite: `dictionary :: nat \<Rightarrow>
dict_entry option` (StarForth_Base.thy:498) was treated as a
fixed, pre-populated table by every theory so far -- FIND/
TRAVERSE/etc. in StarForth_Dictionary_Manipulation_Words.thy
only READ it. This was the first file in the sweep whose primary
job IS insertion (`:`, CREATE, VARIABLE, CONSTANT, DEFER all
call `vm_create_word`). `dict_insert_entry` (defined below) now
models the word_id-assignment/dictionary-table/latest_id/
`word_id_next`-counter portion of `vm_create_word`, reusing the
`word_id_next :: nat` field already declared in StarForth_
Base.thy but never previously written by any theory. What
remains unmodelled per word: `vm_create_word` itself parses no
input (name arrives pre-parsed, but the parse producing that
name is the TIB/input-subsystem gap, present throughout this
suite), does not capture the entry into any per-VM
`vm->compiling_word`-style tracking field (none exists in
vm_state), and callers still mutate the returned `DictEntry*`
directly afterward for flags beyond what `dict_insert_entry`'s
`init_flags` parameter already captures. This is still a
materially bigger gap than the raw-pointer-navigation gap
already flagged in dictionary_manipulation_words.c (which only
reads), even partially closed -- the single largest finding of
this file remains real, just smaller than before.
(b) DATA-FIELD (DF) ADDRESSING: `dict_entry` (StarForth_Base.thy:293)
has no field corresponding to a DictEntry's data-field cell (the
storage `vm_dictionary_get_data_field` returns a pointer into).
CREATE/VARIABLE/CONSTANT's runtimes, DODOES, and does_rt all
read or write this cell -- the exact gap already named for
`>BODY` in StarForth_Dictionary_Manipulation_Words.thy
(`to_body_not_modelled`). Same root cause, different words.
(c) MUTABLE PER-ENTRY DISPATCH: `word_table` (StarForth_Base.thy:626)
is a fixed, uninterpreted global constant -- by design (see that
section's comment), not a per-VM-instance mutable field. DEFER's
`IS` reassigns an entry's *effective* dispatch target at runtime
(stored in the DF cell and read by `defining_runtime_defer`); a
fixed `word_table` cannot express this at all, independent of
gap (b).
LIT additionally treats the top return-stack cell as a raw C
`cell_t*` threaded-code instruction pointer, advanced with C pointer
arithmetic (`rip++`) and dereferenced directly -- NOT as a VM address
resolved through `vm_ptr`/`vm_addr_ok` the way control_words.c's
return-stack-held IP values were (see StarForth_Control_Words.thy's
resume note: that gap turned out to already be covered by `mem_read`
on VM-address-valued return-stack entries). LIT's IP is a genuinely
different, raw-host-pointer usage of the same field; the list-based
`return_stack :: cell list` model has no way to hold or advance a
host pointer.
======================================================================== *)
definition WORD_IMMEDIATE :: nat where "WORD_IMMEDIATE = 0x80"
definition WORD_SMUDGED :: nat where "WORD_SMUDGED = 0x20"
(* ── Dictionary-entry insertion (gap (a), PARTIALLY CLOSED 2026-08-14) ────
`word_id_next` (StarForth_Base.thy, declared but never written by any
theory before this one -- confirmed by grep) is exactly C's
`vm->next_word_id`/`vm_dictionary_acquire_word_id` mechanism
(src/dictionary_management.c:87-92,94-110): a monotonically increasing
counter, one per fresh word, capped at DICTIONARY_SIZE. `vm_create_word`
itself (dictionary_management.c:379-470) does three things this
definition models and one it does not:
1. Pin-shadow guard: scans vm->latest's linked list for a same-name
PINNED entry; refuses (vm->error=1) if found. Sidestepped the same
way StarForth_ACL_Words.thy/StarForth_Physics_Freeze_Words.thy
sidestep the equivalent FIND-shaped dependency: parameterised over
an explicit `pinned_conflict :: bool`, standing in for "whatever a
real name-scan would have found."
2. Allocates a `word_id` via the counter and installs the new entry
into the word-id-indexed table (`vm->word_id_map` / this model's
`dictionary`) -- modelled exactly, both are word_id-indexed.
3. Prepends to `vm->latest`'s linked list, which is also what backs
`latest_id` in this model.
NOT modelled: the real `entry->func` (word_table -- a fixed,
uninterpreted global per StarForth_Base.thy's design, cannot express a
NEW word's dispatch target, which is gap (c)), the physics-metadata
seed (`physics_metadata_init`/`apply_seed` -- modelled as all-zero
`dict_physics`, not the real seeding logic), and the DF cell (gap (b),
unchanged). ACL fields are modelled exactly from the C's literal
initializers (acl_ttl=0, acl_allow=True, acl_mode=ACL_MODE_TTL=0,
acl_pinned=False) -- src/dictionary_management.c:427-430. *)
definition dict_insert_entry :: "string \<Rightarrow> nat \<Rightarrow> bool \<Rightarrow> vm_state \<Rightarrow> vm_state" where
"dict_insert_entry name init_flags pinned_conflict vm =
(if pinned_conflict
then set_error vm
else
let wid = word_id_next vm;
e = \<lparr>de_name = name, de_flags = init_flags, de_heat = 0,
de_word_id = wid,
de_physics = \<lparr>dp_temperature_q8 = 0, dp_last_active_ns = 0,
dp_last_decay_ns = 0, dp_mass_bytes = 0,
dp_avg_latency_ns = 0, dp_state_flags = 0\<rparr>,
de_acl_ttl = 0, de_acl_allow = True, de_acl_mode = ACL_MODE_TTL,
de_acl_pinned = False\<rparr>
in vm\<lparr>dictionary := (dictionary vm)(wid := Some e),
latest_id := Some wid,
word_id_next := wid + 1\<rparr>)"
lemma dict_insert_entry_pinned_conflict_errors:
assumes "pinned_conflict"
shows "vm_error (dict_insert_entry name init_flags pinned_conflict vm)"
by (simp add: dict_insert_entry_def set_error_def assms)
lemma dict_insert_entry_assigns_fresh_word_id:
assumes "\<not> pinned_conflict"
shows "latest_id (dict_insert_entry name init_flags pinned_conflict vm) = Some (word_id_next vm)"
using assms by (simp add: dict_insert_entry_def Let_def)
lemma dict_insert_entry_populates_dictionary:
assumes "\<not> pinned_conflict"
shows "\<exists>e. dictionary (dict_insert_entry name init_flags pinned_conflict vm) (word_id_next vm) = Some e
\<and> de_word_id e = word_id_next vm \<and> de_name e = name \<and> de_flags e = init_flags
\<and> de_heat e = 0 \<and> de_acl_ttl e = 0 \<and> de_acl_allow e \<and> de_acl_mode e = ACL_MODE_TTL
\<and> \<not> de_acl_pinned e"
using assms by (simp add: dict_insert_entry_def Let_def)
lemma dict_insert_entry_advances_counter:
assumes "\<not> pinned_conflict"
shows "word_id_next (dict_insert_entry name init_flags pinned_conflict vm) = word_id_next vm + 1"
using assms by (simp add: dict_insert_entry_def Let_def)
lemma dict_insert_entry_data_stack_unchanged:
"data_stack (dict_insert_entry name init_flags pinned_conflict vm) = data_stack vm"
by (simp add: dict_insert_entry_def set_error_def Let_def)
lemma dict_insert_entry_not_full_word_id_next_bound: True
\<comment> \<open>NOT modelled: the C's `word_id_next >= DICTIONARY_SIZE` exhaustion
branch (dictionary_management.c:87-91,102), which returns
WORD_ID_INVALID and skips the `word_id_map` write while the linked-
list prepend to vm->latest still happens unconditionally regardless.
This model always succeeds at installing into `dictionary` once past
the pin guard -- a real, uncovered edge case (a VM that defines more
than DICTIONARY_SIZE words), not claimed to be handled.\<close>
by simp
(* ── [ ( -- ) : interpret mode, LIVE version (see file header) ──────────── *)
(* C: vm_store_cell(vm, vm->state_addr, 0); vm->mode = MODE_INTERPRET. *)
definition forth_d_left_bracket :: "vm_state \<Rightarrow> vm_state" where
"forth_d_left_bracket vm =
vm\<lparr>memory := mem_write (memory vm) (state_addr vm) 0,
vm_mode := ModeInterpret\<rparr>"
lemma d_left_bracket_sets_interpret:
"vm_mode (forth_d_left_bracket vm) = ModeInterpret"
by (simp add: forth_d_left_bracket_def)
lemma d_left_bracket_writes_state_cell:
"mem_read (memory (forth_d_left_bracket vm)) (state_addr vm) = 0"
by (simp add: forth_d_left_bracket_def mem_read_def mem_write_def)
lemma d_left_bracket_data_stack_unchanged:
"data_stack (forth_d_left_bracket vm) = data_stack vm"
by (simp add: forth_d_left_bracket_def)
lemma d_left_bracket_never_errors:
"vm_error (forth_d_left_bracket vm) = vm_error vm"
by (simp add: forth_d_left_bracket_def)
(* ── ] ( -- ) : compile mode, LIVE version ───────────────────────────────── *)
(* C: vm_store_cell(vm, vm->state_addr, (cell_t)-1); vm->mode = MODE_COMPILE. *)
definition forth_d_right_bracket :: "vm_state \<Rightarrow> vm_state" where
"forth_d_right_bracket vm =
vm\<lparr>memory := mem_write (memory vm) (state_addr vm) (-1),
vm_mode := ModeCompile\<rparr>"
lemma d_right_bracket_sets_compile:
"vm_mode (forth_d_right_bracket vm) = ModeCompile"
by (simp add: forth_d_right_bracket_def)
lemma d_right_bracket_writes_state_cell:
"mem_read (memory (forth_d_right_bracket vm)) (state_addr vm) = -1"
by (simp add: forth_d_right_bracket_def mem_read_def mem_write_def)
lemma d_right_bracket_data_stack_unchanged:
"data_stack (forth_d_right_bracket vm) = data_stack vm"
by (simp add: forth_d_right_bracket_def)
lemma d_right_bracket_never_errors:
"vm_error (forth_d_right_bracket vm) = vm_error vm"
by (simp add: forth_d_right_bracket_def)
lemma d_bracket_right_then_left:
"vm_mode (forth_d_left_bracket (forth_d_right_bracket vm)) = ModeInterpret"
by (simp add: forth_d_left_bracket_def)
lemma d_bracket_left_then_right:
"vm_mode (forth_d_right_bracket (forth_d_left_bracket vm)) = ModeCompile"
by (simp add: forth_d_right_bracket_def)
(* ── STATE ( -- addr ) : LIVE version, pushes a real VM address ─────────── *)
(* C: vm_push(vm, (cell_t)vm->state_addr). Unlike the shadowed dictionary_
manipulation_words.c version (which pushed the address of a dead host
static, and was left unmodelled), this pushes `state_addr` -- a genuine
per-VM field, so this word IS modellable. *)
definition forth_d_state :: "vm_state \<Rightarrow> vm_state" where
"forth_d_state vm =
(if ds_full vm
then set_error vm
else vm\<lparr>data_stack := word_of_nat (state_addr vm) # data_stack vm\<rparr>)"
lemma d_state_normal:
assumes "\<not> ds_full vm"
shows "data_stack (forth_d_state vm) = word_of_nat (state_addr vm) # data_stack vm"
by (simp add: forth_d_state_def assms)
lemma d_state_overflow:
assumes "ds_full vm"
shows "vm_error (forth_d_state vm)"
by (simp add: forth_d_state_def set_error_def assms)
lemma d_state_preserves_state_addr:
"state_addr (forth_d_state vm) = state_addr vm"
by (simp add: forth_d_state_def set_error_def)
(* ── IMMEDIATE ( -- ) : mark latest word immediate, no mode guard ───────── *)
(* C: error if vm->latest is NULL; else vm->latest->flags |= WORD_IMMEDIATE.
Unlike HIDDEN (dictionary_manipulation_words.c), there is no compile-mode
guard at all. *)
definition forth_immediate :: "vm_state \<Rightarrow> vm_state" where
"forth_immediate vm =
(case latest_id vm of
None \<Rightarrow> set_error vm
| Some wid \<Rightarrow>
(case dictionary vm wid of
None \<Rightarrow> set_error vm
| Some e \<Rightarrow>
vm\<lparr>dictionary := (dictionary vm)
(wid := Some (e\<lparr>de_flags := de_flags e OR WORD_IMMEDIATE\<rparr>))\<rparr>))"
lemma immediate_requires_latest:
assumes "latest_id vm = None"
shows "vm_error (forth_immediate vm)"
by (simp add: forth_immediate_def set_error_def assms)
lemma immediate_requires_latest_present_in_dict:
assumes "latest_id vm = Some wid"
assumes "dictionary vm wid = None"
shows "vm_error (forth_immediate vm)"
by (simp add: forth_immediate_def set_error_def assms)
lemma immediate_sets_flag:
assumes "latest_id vm = Some wid"
assumes "dictionary vm wid = Some e"
shows "\<exists>e'. dictionary (forth_immediate vm) wid = Some e' \<and>
de_flags e' = de_flags e OR WORD_IMMEDIATE"
using assms by (simp add: forth_immediate_def)
lemma immediate_data_stack_unchanged:
"data_stack (forth_immediate vm) = data_stack vm"
by (auto simp: forth_immediate_def set_error_def split: option.split)
lemma immediate_no_mode_guard:
\<comment> \<open>Unlike HIDDEN, IMMEDIATE has no `vm_mode vm \<noteq> ModeCompile` check at
all -- when the latest-word guards above are satisfied, its error
status is exactly whatever it was on entry (no NEW error is raised by
a compile-mode check, since there is none). Stated explicitly since
every other flag-setting word in this sweep (SMUDGE, HIDDEN) DOES gate
on compile mode.\<close>
assumes "latest_id vm = Some wid" "dictionary vm wid = Some e"
shows "vm_error (forth_immediate vm) = vm_error vm"
using assms by (simp add: forth_immediate_def)
(* ── : ( "name" -- ) : nested-guard + mode/STATE half only ──────────────── *)
(* C (defining_word_colon + vm_enter_compile_mode): error if already in
MODE_COMPILE (nested ':' is illegal per FORTH-79); else vm->mode =
MODE_COMPILE, vm->state_var = -1, vm_store_cell(vm, vm->state_addr, -1),
THEN vm_create_word(...) -- the entry-creation half, see file header
finding (a), is NOT modelled. Modelled here: guard + the mode/state_var/
state_addr-cell effect, which is state-only and has the identical shape
to `]` plus the extra `state_var` write `]` itself does not do. *)
definition forth_colon_guard :: "vm_state \<Rightarrow> vm_state" where
"forth_colon_guard vm =
(if vm_mode vm = ModeCompile
then set_error vm
else vm\<lparr>vm_mode := ModeCompile,
state_var := -1,
memory := mem_write (memory vm) (state_addr vm) (-1)\<rparr>)"
lemma colon_nested_errors:
assumes "vm_mode vm = ModeCompile"
shows "vm_error (forth_colon_guard vm)"
by (simp add: forth_colon_guard_def set_error_def assms)
lemma colon_sets_compile_mode:
assumes "vm_mode vm \<noteq> ModeCompile"
shows "vm_mode (forth_colon_guard vm) = ModeCompile"
by (simp add: forth_colon_guard_def assms)
lemma colon_sets_state_var:
assumes "vm_mode vm \<noteq> ModeCompile"
shows "state_var (forth_colon_guard vm) = -1"
by (simp add: forth_colon_guard_def assms)
lemma colon_writes_state_cell:
assumes "vm_mode vm \<noteq> ModeCompile"
shows "mem_read (memory (forth_colon_guard vm)) (state_addr vm) = -1"
by (simp add: forth_colon_guard_def mem_read_def mem_write_def assms)
lemma colon_guard_not_full_colon: True
\<comment> \<open>forth_colon_guard is NOT a full model of `:` -- it omits the
dictionary-entry-creation half (`vm_create_word`, `vm->compiling_word`,
WORD_SMUDGED, the DF write of the threaded-body start address). See
file header finding (a)/(b). Named so the omission is greppable.\<close>
by simp
(* ── : entry-creation half, gap (a) PARTIALLY CLOSED 2026-08-14 ──────────
`vm_enter_compile_mode` (src/vm.c:232-264) does forth_colon_guard's
mode/state effect FIRST, then `vm_create_word(...)`, then
`de->flags |= WORD_SMUDGED` on the fresh entry (vm.c:251) -- unlike
CREATE/VARIABLE/CONSTANT, `:` sets a real flag at creation time, so
this reuses `dict_insert_entry WORD_SMUDGED` rather than
`dict_insert_entry 0`. Composed after forth_colon_guard: only valid
when the nested-`:` guard did not already error (real C: vm_create_word
is never reached if `defining_word_colon`'s own nested check fired,
since that returns before calling vm_enter_compile_mode at all). Still
NOT modelled beyond this: name parse, `vm->compiling_word` tracking
(no vm_state counterpart -- would need a new field, not attempted
here), vm_align+HERE capture, and the DF write of the threaded-body
start address (gap b). *)
definition forth_colon_entry_half :: "string \<Rightarrow> bool \<Rightarrow> vm_state \<Rightarrow> vm_state" where
"forth_colon_entry_half name pinned_conflict vm =
dict_insert_entry name WORD_SMUDGED pinned_conflict (forth_colon_guard vm)"
lemma colon_entry_half_requires_guard_to_pass:
assumes "vm_mode vm \<noteq> ModeCompile" "\<not> pinned_conflict"
shows "\<exists>e. dictionary (forth_colon_entry_half name pinned_conflict vm) (word_id_next (forth_colon_guard vm)) = Some e
\<and> de_name e = name \<and> de_flags e = WORD_SMUDGED"
using assms by (simp add: forth_colon_entry_half_def forth_colon_guard_def
dict_insert_entry_def Let_def)
lemma colon_entry_half_still_compile_mode:
assumes "vm_mode vm \<noteq> ModeCompile" "\<not> pinned_conflict"
shows "vm_mode (forth_colon_entry_half name pinned_conflict vm) = ModeCompile"
using assms by (simp add: forth_colon_entry_half_def forth_colon_guard_def
dict_insert_entry_def Let_def)
lemma colon_entry_half_not_full_colon: True
\<comment> \<open>Still NOT modelled: name parse (`name` is a caller-supplied parameter
here, not derived from `forth_parse_word` -- see forth_constant_full
below for the one word in this file where parse IS composed in),
vm->compiling_word tracking (no vm_state field), vm_align+HERE
capture, DF write of the threaded-body start address (gap b). See
section header.\<close>
by simp
(* ── ; ( -- ) : compile-mode guard only ──────────────────────────────────── *)
(* C: error unless vm->mode == MODE_COMPILE; else calls vm_exit_compile_mode,
entirely unmodelled (finds/compiles EXIT, flips WORD_SMUDGED/WORD_COMPILED,
evicts hot-words cache -- none modelled in this suite). *)
definition forth_semicolon_guard :: "vm_state \<Rightarrow> vm_state" where
"forth_semicolon_guard vm = (if vm_mode vm \<noteq> ModeCompile then set_error vm else vm)"
lemma semicolon_requires_compile_mode:
assumes "vm_mode vm \<noteq> ModeCompile"
shows "vm_error (forth_semicolon_guard vm)"
by (simp add: forth_semicolon_guard_def set_error_def assms)
lemma semicolon_guard_not_full_semicolon: True
\<comment> \<open>forth_semicolon_guard covers only the guard raised directly in
defining_word_semicolon. vm_exit_compile_mode's own effects (EXIT
lookup+compile, WORD_SMUDGED/WORD_COMPILED flag flip, hot-words cache
eviction) are entirely unmodelled -- none of EXIT-lookup, per-entry
mutable flags via a live pointer, or the hot-words cache have any
counterpart in this suite's abstract model.\<close>
by simp
(* ── CREATE / VARIABLE / CONSTANT: entry-creation half only, gap (a)
PARTIALLY CLOSED 2026-08-14 ─────────────────────────────────────────────
All three call `vm_create_word(vm, namebuf, nlen, <their own runtime>)`
with no extra flags set afterward (`entry->flags = 0` inside
vm_create_word is the final value) -- so their entry-creation half is
exactly `dict_insert_entry 0`, reused verbatim from the definition
above. NOT modelled, same as before: the name parse that produces
`namebuf`/`nlen` (TIB/input-subsystem gap, present in every word in
this suite that parses a name), CREATE's/VARIABLE's `vm_align`+HERE
capture, VARIABLE's `vm_allot` of one cell, and all three words' DF
write of their respective captured/popped value (gap (b), unchanged).
These are named `forth_<word>_entry_half` deliberately, not
`forth_<word>`, to keep the omission visible at the call site the way
`forth_colon_guard` already does for `:`. *)
definition forth_create_entry_half :: "string \<Rightarrow> bool \<Rightarrow> vm_state \<Rightarrow> vm_state" where
"forth_create_entry_half name pinned_conflict vm = dict_insert_entry name 0 pinned_conflict vm"
definition forth_variable_entry_half :: "string \<Rightarrow> bool \<Rightarrow> vm_state \<Rightarrow> vm_state" where
"forth_variable_entry_half name pinned_conflict vm = dict_insert_entry name 0 pinned_conflict vm"
definition forth_constant_entry_half :: "string \<Rightarrow> bool \<Rightarrow> vm_state \<Rightarrow> vm_state" where
"forth_constant_entry_half name pinned_conflict vm = dict_insert_entry name 0 pinned_conflict vm"
lemma create_entry_half_populates_dictionary:
assumes "\<not> pinned_conflict"
shows "\<exists>e. dictionary (forth_create_entry_half name pinned_conflict vm) (word_id_next vm) = Some e
\<and> de_name e = name \<and> de_flags e = 0"
using assms by (simp add: forth_create_entry_half_def dict_insert_entry_def Let_def)
lemma variable_entry_half_populates_dictionary:
assumes "\<not> pinned_conflict"
shows "\<exists>e. dictionary (forth_variable_entry_half name pinned_conflict vm) (word_id_next vm) = Some e
\<and> de_name e = name \<and> de_flags e = 0"
using assms by (simp add: forth_variable_entry_half_def dict_insert_entry_def Let_def)
lemma constant_entry_half_populates_dictionary:
assumes "\<not> pinned_conflict"
shows "\<exists>e. dictionary (forth_constant_entry_half name pinned_conflict vm) (word_id_next vm) = Some e
\<and> de_name e = name \<and> de_flags e = 0"
using assms by (simp add: forth_constant_entry_half_def dict_insert_entry_def Let_def)
lemma create_entry_half_pinned_conflict_errors:
assumes "pinned_conflict"
shows "vm_error (forth_create_entry_half name pinned_conflict vm)"
using assms by (simp add: forth_create_entry_half_def dict_insert_entry_def set_error_def)
lemma create_entry_half_not_full_create: True
\<comment> \<open>Still NOT modelled beyond entry creation: `name` here is a caller-
supplied parameter, not derived from `forth_parse_word` (see
forth_constant_full below for that composition); also vm_align+HERE
capture and the DF write of the DFA (gap b). See section header.\<close>
by simp
lemma variable_entry_half_not_full_variable: True
\<comment> \<open>Still NOT modelled beyond entry creation: name parse (see note
above), vm_align+HERE capture, vm_allot of one cell, and the DF write
of that cell's address (gap b). See section header.\<close>
by simp
lemma constant_entry_half_not_full_constant: True
\<comment> \<open>Still NOT modelled beyond entry creation: name parse (see note
above -- though see forth_constant_full below, which DOES compose
the parse and the value-pop guard together) and the DF write of the
popped value (gap b). See section header.\<close>
by simp
(* ── CONSTANT, full composition, gap (a)+parse CLOSED for this one word
2026-08-14 ─────────────────────────────────────────────────────────────
Demonstrates end-to-end what StarForth_Base.thy's `forth_parse_word`
(added this session, closing the TIB/name-parse gap named as an
unmodelled precondition throughout this suite) unlocks when composed
with `dict_insert_entry`: CONSTANT's real C order is guard (dsp<0) ->
pop value -> parse name -> vm_create_word. Modelled here exactly in
that order, chosen as the flagship composition because it is this
file's simplest word with a real stack guard (unlike CREATE/VARIABLE,
which have no stack precondition at all). Still NOT modelled: the DF
write of the popped value into the new entry (gap b) -- `value` is
computed and discarded here, faithfully matching everything up to
that point but no further. *)
definition forth_constant_full :: "nat \<Rightarrow> bool \<Rightarrow> vm_state \<Rightarrow> vm_state" where
"forth_constant_full max_len pinned_conflict vm =
(if data_stack vm = []
then set_error vm
else
let vm1 = vm\<lparr>data_stack := tl (data_stack vm)\<rparr>;
(nm, vm2) = forth_parse_word max_len vm1
in if nm = ''''
then set_error vm2
else dict_insert_entry nm 0 pinned_conflict vm2)"
lemma constant_full_underflow:
assumes "data_stack vm = []"
shows "vm_error (forth_constant_full max_len pinned_conflict vm)"
by (simp add: forth_constant_full_def set_error_def assms)
lemma constant_full_success_populates_dictionary:
assumes "data_stack vm \<noteq> []"
assumes "dropWhile is_ws (drop (input_pos vm) (input_buffer vm)) \<noteq> []" (is "?s1 \<noteq> []")
assumes "max_len \<ge> 2"
assumes "\<not> pinned_conflict"
shows "\<exists>e wid. dictionary (forth_constant_full max_len pinned_conflict vm) wid = Some e
\<and> de_name e \<noteq> '''' \<and> de_flags e = 0"
proof -
let ?vm1 = "vm\<lparr>data_stack := tl (data_stack vm)\<rparr>"
obtain nm vm2 where parse_eq: "forth_parse_word max_len ?vm1 = (nm, vm2)" by fastforce
have input_pos_unaffected: "dropWhile is_ws (drop (input_pos ?vm1) (input_buffer ?vm1)) \<noteq> []"
using assms(2) by simp
hence nm_nonempty: "nm \<noteq> ''''"
using forth_parse_word_success_nonempty[OF input_pos_unaffected assms(3)] parse_eq
by (metis fstI)
have "forth_constant_full max_len pinned_conflict vm
= dict_insert_entry nm 0 pinned_conflict vm2"
using assms(1) parse_eq nm_nonempty by (simp add: forth_constant_full_def)
moreover have "\<exists>e. dictionary (dict_insert_entry nm 0 pinned_conflict vm2) (word_id_next vm2) = Some e
\<and> de_name e = nm \<and> de_flags e = 0"
using assms(4) by (simp add: dict_insert_entry_def Let_def)
ultimately show ?thesis using nm_nonempty by auto
qed
lemma create_runtime_not_modelled: True \<comment> \<open>defining_runtime_create: reads current_executing_entry's DF cell (gap b).\<close>
by simp
lemma variable_runtime_not_modelled: True \<comment> \<open>defining_runtime_variable: reads current_executing_entry's DF cell (gap b).\<close>
by simp
lemma constant_runtime_not_modelled: True \<comment> \<open>defining_runtime_constant: reads current_executing_entry's DF cell (gap b).\<close>
by simp
lemma lit_not_modelled: True \<comment> \<open>LIT: reads/advances the return-stack top as a raw C cell_t* threaded-code IP -- see file header, distinct from control_words.c's already-resolved IP-as-vaddr usage.\<close>
by simp
lemma literal_not_modelled: True \<comment> \<open>LITERAL: compiles a literal into threaded code via vm_compile_literal -- depends on the same unmodelled compile-target machinery as `:`/COMPILE.\<close>
by simp
lemma dodoes_not_modelled: True \<comment> \<open>defining_runtime_dodoes: DF/PFA layout (gap b) + runs a raw threaded-code interpreter loop over cell_t* IPs (gap c-adjacent, distinct mechanism from vm_ip).\<close>
by simp
lemma does_rt_not_modelled: True \<comment> \<open>defining_runtime_does_rt: patches vm->latest's DF (gap b) and reassigns its func pointer to defining_runtime_dodoes (gap c).\<close>
by simp
lemma does_greater_not_modelled: True \<comment> \<open>DOES>: compiles does_rt + EXIT into the defining word's body -- same unmodelled compile-target machinery as `:`.\<close>
by simp
lemma compile_not_modelled: True \<comment> \<open>COMPILE: vm_find_word (parse+lookup, same class as FIND, already flagged not-modelled) + vm_compile_word.\<close>
by simp
lemma bracket_compile_not_modelled: True \<comment> \<open>[COMPILE]: identical body to COMPILE (defining_word_bracket_compile IS defining_word_compile).\<close>
by simp
lemma forget_not_modelled: True \<comment> \<open>FORGET: walks vm->latest's raw linked chain by name, frees C structs, and rewinds `here` from a DF read (gap a/b combined) -- categorically the same class of gap as `block_words.c`'s cache-subsystem deferrals: a whole-subsystem project, not a one-word extension.\<close>
by simp
lemma defer_not_modelled: True \<comment> \<open>DEFER: vm_create_word (gap a) with a zeroed DF slot (gap b). CORRECTION (added when src/word_source/defer_words.c was later swept, see StarForth_Defer_Words.thy): word_registry.c registers defer_words.c's DEFER/IS/DEFER@ AFTER this file's (Module 27 vs 17), unconditionally in both builds -- this DEFER is dead, shadowed code, never reachable. The gap analysis below is still accurate as a description of what this dead code would hit, and the live version hits the same gaps anyway, so nothing here needed retracting.\<close>
by simp
lemma defer_runtime_not_modelled: True \<comment> \<open>defining_runtime_defer: reads a DictEntry* out of the DF cell (gap b) and calls through it (gap c). Also shadowed/dead -- see defer_not_modelled correction above.\<close>
by simp
lemma is_not_modelled: True \<comment> \<open>IS: vm_find_word (parse+lookup) + writes an XT into the target's DF cell (gap b) -- the mutable-dispatch mechanism of gap (c). Also shadowed/dead -- see defer_not_modelled correction above.\<close>
by simp
lemma defer_fetch_not_modelled: True \<comment> \<open>DEFER@: vm_find_word + reads the DF cell (gap b). Also shadowed/dead -- see defer_not_modelled correction above.\<close>
by simp
end
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