diff --git a/bin/awl2scl_deep.bat b/bin/awl2scl_deep.bat
new file mode 100644
index 0000000..da68f8f
--- /dev/null
+++ b/bin/awl2scl_deep.bat
@@ -0,0 +1,28 @@
+@echo off
+REM ================================================================
+REM Konvertiert .awl Dateien in .scl Dateien MIT Tiefenoptimierung:
+REM   --improve-gotos    Kontrollfluss aufraeumen (Guard->IF, dedup, CASE)
+REM   --globals2params   globale Merker-Zugriffe in Parameter umbauen
+REM                      (+ toChange-Liste in data\ fuer die Aufrufer)
+REM
+REM Beide Schalter implizieren --force (generierte .scl werden neu erzeugt,
+REM handgeschriebene bleiben geschuetzt).
+REM
+REM Weitere Argumente werden durchgereicht, z.B.:
+REM   bin\awl2scl_deep.bat --dir . --category A
+REM   bin\awl2scl_deep.bat <baustein.awl> ...
+REM ================================================================
+
+call "%~dp0setenv.bat"
+
+REM .venv bevorzugen, sonst System-Python
+set "PYTHON=python"
+if exist "%PROJECT%\.venv\Scripts\python.exe" (
+    set "PYTHON=%PROJECT%\.venv\Scripts\python.exe"
+)
+
+"%PYTHON%" "%PV_LIB%\awl2scl.py" --improve-gotos --globals2params %*
+if errorlevel 1 (
+    echo FEHLER: awl2scl.py wurde mit Fehler beendet.
+    exit /b 1
+)
diff --git a/bin/setenv.bat b/bin/setenv.bat
index 022da40..dc57765 100644
--- a/bin/setenv.bat
+++ b/bin/setenv.bat
@@ -38,6 +38,7 @@ if not exist "%PV_BIN%" mkdir "%PV_BIN%"
 if not exist "%PV_LIB%" mkdir "%PV_LIB%"
 if not exist "%PV_CFG%" mkdir "%PV_CFG%"
 if not exist "%PV_DATA%" mkdir "%PV_DATA%"
+if not exist "%PV_DOC%" mkdir "%PV_DOC%"
 if not exist "%PV_TESTS%" mkdir "%PV_TESTS%"
 if not exist "%PV_SCL_EXPORT%" mkdir "%PV_SCL_EXPORT%"
 
@@ -45,15 +46,15 @@ REM Umgebungsvariablen anzeigen
 echo.
 echo ================================================================
 echo PROJECT      = %PROJECT%
-echo PV_BIN       = %PV_BIN%
-echo PV_LIB       = %PV_LIB%
-echo PV_CFG       = %PV_CFG%
-echo PV_DATA      = %PV_DATA%
-echo PV_LOG       = %PV_LOG%
-echo PV_RESULTS   = %PV_RESULTS%
-echo PV_EXAMPLES  = %PV_EXAMPLES%
-echo PV_TESTS     = %PV_TESTS%
-echo PV_SCL_EXPORT= %PV_SCL_EXPORT%
-echo PYTHONPATH   = %PYTHONPATH%
+@REM echo PV_BIN       = %PV_BIN%
+@REM echo PV_LIB       = %PV_LIB%
+@REM echo PV_CFG       = %PV_CFG%
+@REM echo PV_DATA      = %PV_DATA%
+@REM echo PV_LOG       = %PV_LOG%
+@REM echo PV_RESULTS   = %PV_RESULTS%
+@REM echo PV_EXAMPLES  = %PV_EXAMPLES%
+@REM echo PV_TESTS     = %PV_TESTS%
+@REM echo PV_SCL_EXPORT= %PV_SCL_EXPORT%
+@REM echo PYTHONPATH   = %PYTHONPATH%
 echo ================================================================
 echo.
diff --git a/lib/paramize.py b/lib/paramize.py
new file mode 100644
index 0000000..2f1abaa
--- /dev/null
+++ b/lib/paramize.py
@@ -0,0 +1,424 @@
+#!/usr/bin/env python3
+"""globals2params: baut globale Merker-Zugriffe eines Bausteins in echte
+Parameter um und verwaltet eine persistente toChange-Liste in data/ fuer die
+Anpassung der Aufrufer (auch noch nicht konvertierter .awl-Dateien).
+
+Verhalten (verhaltenserhaltend by construction): ein Global, das der Baustein
+bisher direkt las/schrieb, wird Parameter; jeder Aufrufer forwardet exakt
+dasselbe Global an den Parameter (Input ':=', Output/InOut '=>'). Damit bleibt
+die Semantik identisch, solange der Aufrufer das Global vor/nach dem Aufruf
+wie bisher nutzt.
+
+Grenzen: indirekte Aufrufe (UC/CC FC[var]) koennen nicht automatisch
+umgeschrieben werden -> in toChange als 'manual' vermerkt.
+"""
+import json
+import re
+from pathlib import Path
+
+import sclopt
+
+
+# Globale Operanden: symbolisch ("...") oder absolut (M/E/A/PE/PA + Groesse).
+# Lokale (#...), Literale, Timer/Zaehler (T/C mit Nummer) sind KEINE Kandidaten.
+_ABS_GLOBAL_RE = re.compile(r'^(M|E|A|PE|PA|I|Q)(X|B|W|D)?\d+(\.\d+)?$')
+_SYM_GLOBAL_RE = re.compile(r'^"[^"]+"$')
+
+
+def is_global_operand(tok):
+    tok = tok.strip()
+    if not tok or tok.startswith("#"):
+        return False
+    if _SYM_GLOBAL_RE.match(tok):
+        return True
+    return bool(_ABS_GLOBAL_RE.match(tok))
+
+
+def param_name_for(global_tok):
+    """Deterministischer, SCL-gueltiger Parametername aus dem Global-Token."""
+    core = global_tok.strip().strip('"')
+    name = re.sub(r"[^A-Za-z0-9_]", "_", core)
+    if not re.match(r"^[A-Za-z_]", name):
+        name = "g_" + name
+    return name
+
+
+# ---------------------------------------------------------------------------
+# Richtungsanalyse ueber die IR-Knoten
+# ---------------------------------------------------------------------------
+
+_TOKEN_RE = re.compile(r'"[^"]+"|#?[A-Za-z_]\w*(?:\.\w+)*|\b\d+\b')
+
+
+def _iter_read_tokens(expr):
+    """Alle Operanden-Token eines SCL-Ausdrucks (fuer Lese-Erkennung)."""
+    if not expr:
+        return
+    for m in re.finditer(r'"[^"]+"|#[A-Za-z_][\w.]*|[A-Za-z_][\w.]*', expr):
+        yield m.group(0)
+
+
+def _base_token(tok):
+    """Strukturzugriff auf Basis reduzieren: '"DB".Feld' -> '"DB"'; 'M10.0' bleibt."""
+    tok = tok.strip()
+    if tok.startswith('"'):
+        end = tok.find('"', 1)
+        return tok[:end + 1] if end != -1 else tok
+    return tok
+
+
+_CALL_HEAD_RE = re.compile(r'^\s*(?:#\w+|"[^"]+")\s*\(')
+
+
+def _call_param_values(call_text):
+    """Liefert die Parameter-WERTE (rechts von := / =>) eines SCL-Aufrufs.
+    Zielbaustein und Parameternamen werden ausgelassen."""
+    m = _CALL_HEAD_RE.match(call_text)
+    if not m:
+        return
+    inner = call_text[m.end():]
+    depth = 1
+    end = 0
+    dq = sq = False
+    for i, ch in enumerate(inner):
+        if ch == '"' and not sq:
+            dq = not dq
+        elif ch == "'" and not dq:
+            sq = not sq
+        elif ch in "([" and not dq and not sq:
+            depth += 1
+        elif ch in ")]" and not dq and not sq:
+            depth -= 1
+            if depth == 0:
+                end = i
+                break
+    inner = inner[:end]
+    for piece in _split_commas(inner):
+        for sep in (":=", "=>"):
+            if sep in piece:
+                yield piece.split(sep, 1)[1].strip()
+                break
+
+
+def _split_commas(text):
+    parts, buf, depth, dq, sq = [], [], 0, False, False
+    for ch in text:
+        if ch == '"' and not sq:
+            dq = not dq
+        elif ch == "'" and not dq:
+            sq = not sq
+        elif ch in "([" and not dq and not sq:
+            depth += 1
+        elif ch in ")]" and not dq and not sq:
+            depth -= 1
+        if ch == "," and depth == 0 and not dq and not sq:
+            parts.append("".join(buf)); buf = []; continue
+        buf.append(ch)
+    parts.append("".join(buf))
+    return parts
+
+
+def analyze_directions(nodes, reads, writes):
+    """Fuellt reads/writes (Sets globaler Basis-Token) durch Rekursion ueber die IR."""
+    for n in nodes:
+        if isinstance(n, sclopt.Assign):
+            base = _base_token(n.lhs)
+            if is_global_operand(base):
+                writes.add(base)
+            for t in _iter_read_tokens(n.rhs):
+                b = _base_token(t)
+                if is_global_operand(b):
+                    reads.add(b)
+        elif isinstance(n, sclopt.IfDo):
+            for t in _iter_read_tokens(n.cond):
+                b = _base_token(t)
+                if is_global_operand(b):
+                    reads.add(b)
+            analyze_directions(n.body, reads, writes)
+        elif isinstance(n, sclopt.Case):
+            b = _base_token(n.selector)
+            if is_global_operand(b):
+                reads.add(b)
+            for _, body, _ in n.branches:
+                analyze_directions(body, reads, writes)
+        elif isinstance(n, sclopt.Call):
+            # Nur die Parameter-WERTE eines Aufrufs sind Global-Kandidaten,
+            # nicht der Zielbaustein und nicht die Parameternamen.
+            for value in _call_param_values(n.text):
+                b = _base_token(value)
+                if is_global_operand(b):
+                    reads.add(b)
+                    writes.add(b)  # Aufrufparameter: Richtung unklar -> konservativ InOut
+
+
+# ---------------------------------------------------------------------------
+# IR-Umschreibung: Global-Token -> #Parameter
+# ---------------------------------------------------------------------------
+
+def _replace_in_expr(expr, mapping):
+    if not expr:
+        return expr
+    def repl(m):
+        tok = m.group(0)
+        base = _base_token(tok)
+        if base in mapping:
+            return mapping[base] + tok[len(base):]
+        return tok
+    return re.sub(r'"[^"]+"(?:\.\w+)*|#?[A-Za-z_][\w.]*', repl, expr)
+
+
+def _rewrite_call_values(call_text, mapping):
+    """Ersetzt in einem Aufruf nur die Parameter-Werte (rechts von :=/=>)."""
+    m = _CALL_HEAD_RE.match(call_text)
+    if not m:
+        return call_text
+    head = call_text[:m.end()]
+    rest = call_text[m.end():]
+    depth = 1
+    end = 0
+    dq = sq = False
+    for i, ch in enumerate(rest):
+        if ch == '"' and not sq:
+            dq = not dq
+        elif ch == "'" and not dq:
+            sq = not sq
+        elif ch in "([" and not dq and not sq:
+            depth += 1
+        elif ch in ")]" and not dq and not sq:
+            depth -= 1
+            if depth == 0:
+                end = i
+                break
+    inner, tail = rest[:end], rest[end:]
+    new_pieces = []
+    for piece in _split_commas(inner):
+        for sep in (":=", "=>"):
+            if sep in piece:
+                name, value = piece.split(sep, 1)
+                new_pieces.append(f"{name}{sep}{_replace_in_expr(value, mapping)}")
+                break
+        else:
+            new_pieces.append(piece)
+    return head + ",".join(new_pieces) + tail
+
+
+def rewrite_nodes(nodes, mapping):
+    for n in nodes:
+        if isinstance(n, sclopt.Assign):
+            n.lhs = _replace_in_expr(n.lhs, mapping)
+            n.rhs = _replace_in_expr(n.rhs, mapping)
+        elif isinstance(n, sclopt.IfDo):
+            n.cond = _replace_in_expr(n.cond, mapping)
+            rewrite_nodes(n.body, mapping)
+        elif isinstance(n, sclopt.Case):
+            n.selector = _replace_in_expr(n.selector, mapping)
+            for _, body, _ in n.branches:
+                rewrite_nodes(body, mapping)
+        elif isinstance(n, sclopt.Call):
+            n.text = _rewrite_call_values(n.text, mapping)
+
+
+# ---------------------------------------------------------------------------
+# Aufrufer-Suche in allen .awl-Quellen
+# ---------------------------------------------------------------------------
+
+def _station_of(path):
+    for part in Path(path).parts:
+        if part.startswith("=A"):
+            return part
+    return "_"
+
+
+class CallerIndex:
+    """Findet direkte und indirekte Aufrufer je Bausteinname, ueber .awl-Quellen."""
+
+    def __init__(self, roots):
+        self.direct = {}     # name -> list[(station, caller_name, path)]
+        self.indirect = {}   # name -> list[(station, caller_name, path)]  (UC/CC FC[..])
+        self._build(roots)
+
+    def _build(self, roots):
+        awl_files = []
+        for root in roots:
+            awl_files.extend(Path(root).rglob("*.awl"))
+        direct_re = re.compile(r'\bCALL\s+(?:FB|FC|SFB|SFC)?\s*"([^"]+)"')
+        indirect_re = re.compile(r'\b(?:UC|CC)\s+FC\[')
+        header_re = re.compile(r'===\s*\w+\s+\S*:\s*(.+?)\s*\[STL\]\s*===|'
+                               r'^(?:FUNCTION_BLOCK|FUNCTION|ORGANIZATION_BLOCK)\s+"([^"]+)"')
+        for p in awl_files:
+            try:
+                text = p.read_text(encoding="utf-8-sig", errors="replace")
+            except OSError:
+                continue
+            hm = header_re.search(text)
+            caller = (hm.group(1) or hm.group(2)) if hm else p.stem
+            station = _station_of(p)
+            for m in direct_re.finditer(text):
+                self.direct.setdefault(m.group(1), []).append((station, caller, str(p)))
+            if indirect_re.search(text):
+                self.indirect.setdefault("*", []).append((station, caller, str(p)))
+
+
+# ---------------------------------------------------------------------------
+# toChange-Persistenz
+# ---------------------------------------------------------------------------
+
+class ToChangeStore:
+    """data/globals2params_tochange.json:
+    { "<station>|<caller>": { "path":..., "changes":[ {func, call, status} ] } }"""
+
+    def __init__(self, path):
+        self.path = Path(path)
+        self.data = {}
+        if self.path.exists():
+            try:
+                self.data = json.loads(self.path.read_text(encoding="utf-8"))
+            except (OSError, ValueError):
+                self.data = {}
+
+    @staticmethod
+    def key(station, caller):
+        return f"{station}|{caller}"
+
+    def add_change(self, station, caller, path, func, call_text, status):
+        k = self.key(station, caller)
+        entry = self.data.setdefault(k, {"path": path, "changes": []})
+        for ch in entry["changes"]:
+            if ch["func"] == func:
+                ch["call"] = call_text
+                ch["status"] = status
+                return
+        entry["changes"].append({"func": func, "call": call_text, "status": status})
+
+    def pending_for(self, station, caller):
+        entry = self.data.get(self.key(station, caller))
+        if not entry:
+            return []
+        return [ch for ch in entry["changes"] if ch.get("status") == "pending"]
+
+    def mark_applied(self, station, caller, func):
+        entry = self.data.get(self.key(station, caller))
+        if not entry:
+            return
+        for ch in entry["changes"]:
+            if ch["func"] == func:
+                ch["status"] = "applied"
+
+    def save(self):
+        self.path.parent.mkdir(parents=True, exist_ok=True)
+        self.path.write_text(json.dumps(self.data, indent=2, ensure_ascii=False), encoding="utf-8")
+
+
+# ---------------------------------------------------------------------------
+# Orchestrierung
+# ---------------------------------------------------------------------------
+
+class Paramizer:
+    def __init__(self, caller_index, store):
+        self.caller_index = caller_index
+        self.store = store
+
+    def parameterize(self, parsed, translated, translator, station, awl_path):
+        """Baut globale Zugriffe des Bausteins in Parameter um; erzeugt toChange
+        fuer alle Aufrufer. Liefert (new_params, callers)."""
+        reads, writes = set(), set()
+        for _, nodes in translated:
+            analyze_directions(nodes, reads, writes)
+        globals_used = reads | writes
+        if not globals_used:
+            return [], []
+
+        # Richtung + Parametername je Global
+        params = []   # (global, name, direction)
+        mapping = {}  # global-basis -> "#name"
+        used_names = set()
+        for g in sorted(globals_used):
+            r, w = g in reads, g in writes
+            direction = "InOut" if (r and w) else ("Output" if w else "Input")
+            name = param_name_for(g)
+            while name in used_names:
+                name += "_"
+            used_names.add(name)
+            params.append((g, name, direction))
+            mapping[g] = "#" + name
+
+        # Interface ergaenzen (Kommentar: war "<global>")
+        for g, name, direction in params:
+            sect = {"Input": "Input", "Output": "Output", "InOut": "InOut"}[direction]
+            parsed.sections.setdefault(sect, []).append(f'{name} : {_scl_type_for(g)};   // war {g}')
+
+        # Rumpf umschreiben
+        for _, nodes in translated:
+            rewrite_nodes(nodes, mapping)
+
+        # Aufrufer + toChange
+        callers = self._record_callers(parsed.name, params)
+        return params, callers
+
+    def _record_callers(self, func_name, params):
+        results = []
+        call_text = _build_param_call(func_name, params)
+        for station, caller, path in self.caller_index.direct.get(func_name, []):
+            self.store.add_change(station, caller, path, func_name, call_text, "pending")
+            results.append((f"{station}|{caller}", "pending"))
+        # indirekte Aufrufe (UC/CC FC[..]) -> manuell
+        for station, caller, path in self.caller_index.indirect.get("*", []):
+            self.store.add_change(station, caller, path, func_name,
+                                  f"// MANUELL: indirekter Aufruf von {func_name} auf Parameter umstellen",
+                                  "manual")
+            results.append((f"{station}|{caller}", "manual"))
+        return results
+
+    def apply_pending_call_rewrites(self, parsed, translated, station):
+        """Wendet frueher vermerkte Aufruf-Rewrites an, wenn DIESER Baustein
+        (als Aufrufer) jetzt konvertiert wird."""
+        pending = self.store.pending_for(station, parsed.name)
+        if not pending:
+            return
+        by_func = {ch["func"]: ch["call"] for ch in pending}
+        for _, nodes in translated:
+            _rewrite_calls_in_nodes(nodes, by_func)
+        for ch in pending:
+            self.store.mark_applied(station, parsed.name, ch["func"])
+
+
+def _scl_type_for(global_tok):
+    """Grobe Typableitung aus dem Global-Token (mechanisch, im Zweifel Bool/Word)."""
+    core = global_tok.strip().strip('"')
+    m = re.match(r'^(M|E|A|PE|PA|I|Q)(X|B|W|D)?', core)
+    if m:
+        return {"X": "Bool", "B": "Byte", "W": "Word", "D": "DWord", None: "Bool"}[m.group(2)]
+    if "." in core or re.search(r"\d+\.\d+$", core):
+        return "Bool"
+    return "Word"
+
+
+def _build_param_call(func_name, params):
+    parts = []
+    for g, name, direction in params:
+        sep = ":=" if direction == "Input" else "=>"
+        parts.append(f"{name} {sep} {g}")
+    return f'"{func_name}"(' + ", ".join(parts) + ");"
+
+
+def _rewrite_calls_in_nodes(nodes, by_func):
+    call_name_re = re.compile(r'^"([^"]+)"\s*\(')
+    for i, n in enumerate(nodes):
+        if isinstance(n, sclopt.Call):
+            m = call_name_re.match(n.text.strip())
+            if m and m.group(1) in by_func:
+                nodes[i] = sclopt.Call(by_func[m.group(1)], n.comment)
+        elif isinstance(n, sclopt.IfDo):
+            _rewrite_calls_in_nodes(n.body, by_func)
+        elif isinstance(n, sclopt.Case):
+            for _, body, _ in n.branches:
+                _rewrite_calls_in_nodes(body, by_func)
+
+
+class NullParamizer:
+    """Platzhalter, wenn --globals2params aus ist (keine Umbauten)."""
+    def parameterize(self, *a, **k):
+        return [], []
+
+    def apply_pending_call_rewrites(self, *a, **k):
+        return
diff --git a/lib/sclopt.py b/lib/sclopt.py
new file mode 100644
index 0000000..9b208c0
--- /dev/null
+++ b/lib/sclopt.py
@@ -0,0 +1,493 @@
+#!/usr/bin/env python3
+"""SCL-Zwischenstruktur (IR) + Lesbarkeits-Optimierung fuer awl2scl.py.
+
+Der Translator in awl2scl.py erzeugt IR-Knoten (statt direkt Textzeilen);
+render_ir() rendert sie. Ohne aktive Optimierung ist die Ausgabe
+byte-identisch zur frueheren stringbasierten Emission (Regressionsabsicherung).
+
+Mit --improve-gotos laufen verlustfreie Peephole-Durchlaeufe:
+  - merge_adjacent_ifdo  : gleiche Bedingung zusammenfassen
+  - guard_skip_to_if     : "IF c THEN GOTO L; body; L:" -> "IF NOT c THEN body"
+  - synth_case           : Verteilung auf eine Variable -> CASE
+  - drop_unused_labels   : nicht angesprungene Marken entfernen
+  - normalize_bool       : Klammern/NOT vereinfachen
+"""
+import re
+
+
+# ---------------------------------------------------------------------------
+# IR-Knoten
+# ---------------------------------------------------------------------------
+
+class Node:
+    comment = ""
+
+    def render(self):
+        raise NotImplementedError
+
+
+class Raw(Node):
+    """Beliebige vorgefertigte Zeile (Fallback, z.B. Kommentare, ENO-Zeilen)."""
+    def __init__(self, text):
+        self.text = text
+
+    def render(self):
+        return [self.text]
+
+
+class Comment(Node):
+    def __init__(self, text):
+        self.text = text
+
+    def render(self):
+        return [f"// {self.text}"]
+
+
+class Label(Node):
+    def __init__(self, name):
+        self.name = name
+
+    def render(self):
+        return [f"{self.name}: ;"]
+
+
+class Goto(Node):
+    def __init__(self, target):
+        self.target = target
+
+    def render(self):
+        return [f"GOTO {self.target};"]
+
+
+class Return(Node):
+    def render(self):
+        return ["RETURN;"]
+
+
+class Assign(Node):
+    def __init__(self, lhs, rhs, comment=""):
+        self.lhs = lhs
+        self.rhs = rhs
+        self.comment = comment
+
+    def render(self):
+        line = f"{self.lhs} := {self.rhs};"
+        if self.comment:
+            line += f"   // {self.comment}"
+        return [line]
+
+
+class Call(Node):
+    def __init__(self, text, comment=""):
+        self.text = text
+        self.comment = comment
+
+    def render(self):
+        line = self.text
+        if self.comment:
+            line += f"   // {self.comment}"
+        return [line]
+
+
+class IfDo(Node):
+    """Bedingte Ausfuehrung. body ist eine Liste von Node.
+    single_line=True rendert die urspruengliche einzeilige Form
+    'IF c THEN <stmt> END_IF;' (fuer Byte-Identitaet der mechanischen Ausgabe)."""
+    def __init__(self, cond, body, single_line=True):
+        self.cond = cond
+        self.body = body
+        self.single_line = single_line
+
+    def render(self):
+        if self.single_line and len(self.body) == 1:
+            inner = self.body[0].render()
+            if len(inner) == 1:
+                return [f"IF {self.cond} THEN {inner[0]} END_IF;"]
+        out = [f"IF {self.cond} THEN"]
+        for n in self.body:
+            for ln in n.render():
+                out.append("   " + ln)
+        out.append("END_IF;")
+        return out
+
+
+class Case(Node):
+    """CASE selector OF <konst[,konst]>: <body> ... END_CASE;"""
+    def __init__(self, selector, branches):
+        self.selector = selector
+        self.branches = branches  # list of (labels:list[str], body:list[Node], comment:str)
+
+    def render(self):
+        out = [f"CASE {self.selector} OF"]
+        for labels, body, comment in self.branches:
+            head = "   " + ", ".join(labels) + ":"
+            if comment:
+                head += f"   // {comment}"
+            out.append(head)
+            for n in body:
+                for ln in n.render():
+                    out.append("      " + ln)
+        out.append("END_CASE;")
+        return out
+
+
+# ---------------------------------------------------------------------------
+# Rendern
+# ---------------------------------------------------------------------------
+
+def render_ir(nodes):
+    lines = []
+    for n in nodes:
+        lines.extend(n.render())
+    return lines
+
+
+# ---------------------------------------------------------------------------
+# Hilfen: Bedingungen/Ausdruecke
+# ---------------------------------------------------------------------------
+
+def _find_matching(expr, open_idx):
+    """Index der zu expr[open_idx]=='(' passenden ')'."""
+    depth = 0
+    dq = sq = False
+    for i in range(open_idx, len(expr)):
+        ch = expr[i]
+        if ch == '"' and not sq:
+            dq = not dq
+        elif ch == "'" and not dq:
+            sq = not sq
+        elif ch == "(" and not dq and not sq:
+            depth += 1
+        elif ch == ")" and not dq and not sq:
+            depth -= 1
+            if depth == 0:
+                return i
+    return -1
+
+
+def strip_outer_parens(expr):
+    """Entfernt genau umschliessende aeussere Klammern (mehrfach), verlustfrei."""
+    expr = expr.strip()
+    while expr.startswith("(") and _find_matching(expr, 0) == len(expr) - 1:
+        expr = expr[1:-1].strip()
+    return expr
+
+
+def collapse_double_parens(expr):
+    """'((x))' -> '(x)' wo die inneren Klammern direkt die aeusseren fuellen."""
+    changed = True
+    while changed:
+        changed = False
+        i = 0
+        while i < len(expr) - 1:
+            if expr[i] == "(" and expr[i + 1] == "(":
+                close = _find_matching(expr, i)
+                inner_close = _find_matching(expr, i + 1)
+                if close != -1 and inner_close == close - 1:
+                    expr = expr[:i] + expr[i + 1:close] + expr[close + 1:]
+                    changed = True
+                    continue
+            i += 1
+    return expr
+
+
+def normalize_cond(cond):
+    """Verlustfreie Ausdrucks-Kosmetik: doppelte/aeussere Klammern weg,
+    NOT (a = b) -> a <> b, NOT (a <> b) -> a = b, NOT (NOT x) -> x."""
+    prev = None
+    cond = cond.strip()
+    while cond != prev:
+        prev = cond
+        cond = collapse_double_parens(cond)
+        # NOT (NOT x) -> x
+        m = re.match(r"^NOT \((NOT \(.*\))\)$", cond)
+        if m and _find_matching(cond, 4) == len(cond) - 1:
+            cond = strip_outer_parens(cond[4:])  # innere NOT(...) behalten
+            continue
+        # NOT (a <op> b) mit einzelnem Vergleich -> negierter Vergleich
+        m = re.match(r"^NOT \((.*)\)$", cond)
+        if m and _find_matching(cond, 4) == len(cond) - 1:
+            inner = m.group(1).strip()
+            flip = _flip_comparison(inner)
+            if flip is not None:
+                cond = flip
+                continue
+        cond2 = strip_outer_parens(cond)
+        if cond2 != cond:
+            cond = cond2
+    return cond
+
+
+_CMP_FLIP = {"=": "<>", "<>": "=", ">": "<=", "<": ">=", ">=": "<", "<=": ">"}
+_CMP_RE = re.compile(r"^(.*?)\s(<>|>=|<=|=|>|<)\s(.*)$")
+
+
+def _flip_comparison(inner):
+    """Falls inner ein einzelner Top-Level-Vergleich ist: negierten Vergleich zurueck."""
+    inner = strip_outer_parens(inner)
+    # Nur genau EIN Top-Level-Vergleich, keine AND/OR-Verknuepfung auf Top-Ebene.
+    if _has_top_level_boolop(inner):
+        return None
+    m = _CMP_RE.match(inner)
+    if not m:
+        return None
+    lhs, op, rhs = m.group(1).strip(), m.group(2), m.group(3).strip()
+    if _has_top_level_boolop(lhs) or _has_top_level_boolop(rhs):
+        return None
+    return f"{lhs} {_CMP_FLIP[op]} {rhs}"
+
+
+def _has_top_level_boolop(expr):
+    depth = 0
+    dq = sq = False
+    tokens = re.finditer(r'"|\'|\(|\)|\bAND\b|\bOR\b|\bXOR\b', expr)
+    for m in tokens:
+        t = m.group(0)
+        if t == '"' and not sq:
+            dq = not dq
+        elif t == "'" and not dq:
+            sq = not sq
+        elif t == "(" and not dq and not sq:
+            depth += 1
+        elif t == ")" and not dq and not sq:
+            depth -= 1
+        elif t in ("AND", "OR", "XOR") and depth == 0 and not dq and not sq:
+            return True
+    return False
+
+
+def negate_cond(cond):
+    """Logische Negation einer Bedingung (fuer Guard-Umkehr)."""
+    cond = cond.strip()
+    inner = strip_outer_parens(cond)
+    flip = _flip_comparison(inner)
+    if flip is not None:
+        return flip
+    if inner.startswith("NOT (") and _find_matching(inner, 4) == len(inner) - 1:
+        return strip_outer_parens(inner[4:])
+    return f"NOT ({inner})"
+
+
+# ---------------------------------------------------------------------------
+# Improve-Passes (verlustfrei)
+# ---------------------------------------------------------------------------
+
+def _referenced_labels(nodes):
+    refs = {}
+    for n in nodes:
+        if isinstance(n, Goto):
+            refs[n.target] = refs.get(n.target, 0) + 1
+        elif isinstance(n, IfDo):
+            for b in n.body:
+                if isinstance(b, Goto):
+                    refs[b.target] = refs.get(b.target, 0) + 1
+    return refs
+
+
+def merge_adjacent_ifdo(nodes):
+    out = []
+    for n in nodes:
+        if (isinstance(n, IfDo) and out and isinstance(out[-1], IfDo)
+                and out[-1].cond == n.cond):
+            out[-1] = IfDo(out[-1].cond, out[-1].body + n.body, single_line=False)
+        else:
+            out.append(n)
+    return out
+
+
+def guard_skip_to_if(nodes):
+    """IfDo(c,[Goto L]); <B ohne L/Sprung nach L>; Label(L)  ->  IfDo(not c, B)
+    Nur wenn L genau einmal referenziert wird und direkt hinter B steht."""
+    refs = _referenced_labels(nodes)
+    out = []
+    i = 0
+    n = len(nodes)
+    while i < n:
+        node = nodes[i]
+        if (isinstance(node, IfDo) and len(node.body) == 1
+                and isinstance(node.body[0], Goto)
+                and refs.get(node.body[0].target, 0) == 1):
+            target = node.body[0].target
+            # Block B bis zur passenden Label(target) sammeln
+            j = i + 1
+            body = []
+            found = False
+            while j < n:
+                if isinstance(nodes[j], Label) and nodes[j].name == target:
+                    found = True
+                    break
+                if isinstance(nodes[j], Label):
+                    break  # andere Marke dazwischen -> kein sauberes Guard-Muster
+                body.append(nodes[j])
+                j += 1
+            if found and body:
+                inv = normalize_cond(negate_cond(node.cond))
+                out.append(IfDo(inv, guard_skip_to_if(body), single_line=(len(body) == 1)))
+                i = j + 1  # Label(target) ueberspringen
+                continue
+        out.append(node)
+        i += 1
+    return out
+
+
+_EQ_RE = re.compile(r"^(.*?)\s=\s(.+)$")
+
+
+def _eq_dispatch(cond):
+    """Wenn cond ein einzelner '<sel> = <konst>' ist: (sel, konst), sonst None."""
+    cond = strip_outer_parens(cond)
+    if _has_top_level_boolop(cond):
+        return None
+    m = _EQ_RE.match(cond)
+    if not m:
+        return None
+    sel, const = m.group(1).strip(), m.group(2).strip()
+    if not re.match(r'^(#?\w+|"[^"]+")$', sel):
+        return None
+    if not re.match(r"^(16#[0-9A-Fa-f]+|w#16#[0-9A-Fa-f]+|\d+|W#\d+)$", const, re.IGNORECASE):
+        return None
+    return sel, const
+
+
+def _body_key(body):
+    return "\n".join(render_ir(body))
+
+
+def synth_case(nodes):
+    """Folge von IfDo(sel = const, body) auf denselben sel -> Case.
+    Bodies, die auf Return enden, werden im CASE ohne das Return uebernommen."""
+    out = []
+    i = 0
+    n = len(nodes)
+    while i < n:
+        node = nodes[i]
+        disp = None
+        if isinstance(node, IfDo):
+            disp = _eq_dispatch(node.cond)
+        if disp is None:
+            out.append(node)
+            i += 1
+            continue
+        sel = disp[0]
+        # Alle direkt folgenden Dispatch-IfDo auf denselben sel sammeln
+        group = []
+        j = i
+        consts_seen = set()
+        while j < n and isinstance(nodes[j], IfDo):
+            d = _eq_dispatch(nodes[j].cond)
+            if d is None or d[0] != sel or d[1] in consts_seen:
+                break
+            consts_seen.add(d[1])
+            group.append((d[1], nodes[j].body))
+            j += 1
+        if len(group) < 2:
+            out.append(node)
+            i += 1
+            continue
+        # Bodies bereinigen (trailing Return entfernen) und gleiche zusammenfassen
+        branches = []
+        for const, body in group:
+            b = list(body)
+            if b and isinstance(b[-1], Return):
+                b = b[:-1]
+            key = _body_key(b)
+            for lab in branches:
+                if lab[2] == key:
+                    lab[0].append(const)
+                    break
+            else:
+                branches.append([[const], b, key])
+        out.append(Case(sel, [(labs, body, "") for labs, body, _ in branches]))
+        i = j
+    return out
+
+
+def drop_unused_labels(nodes):
+    refs = _referenced_labels(nodes)
+    return [n for n in nodes if not (isinstance(n, Label) and refs.get(n.name, 0) == 0)]
+
+
+def normalize_bool_pass(nodes):
+    for n in nodes:
+        if isinstance(n, IfDo):
+            n.cond = normalize_cond(n.cond)
+            normalize_bool_pass(n.body)
+        elif isinstance(n, Assign):
+            n.rhs = normalize_cond(n.rhs) if _looks_boolean(n.rhs) else n.rhs
+        elif isinstance(n, Case):
+            for _, body, _ in n.branches:
+                normalize_bool_pass(body)
+    return nodes
+
+
+def _looks_boolean(rhs):
+    return bool(re.search(r"\b(AND|OR|XOR|NOT)\b", rhs)) or rhs.strip().startswith("(")
+
+
+def improve_gotos(nodes):
+    """Alle Passes in sinnvoller Reihenfolge; verlustfrei (je Netzwerk)."""
+    nodes = merge_adjacent_ifdo(nodes)
+    nodes = guard_skip_to_if(nodes)
+    nodes = synth_case(nodes)
+    nodes = drop_unused_labels(nodes)
+    nodes = normalize_bool_pass(nodes)
+    return nodes
+
+
+def _region_single_dispatch(nodes):
+    """Wenn eine REGION (nach improve_gotos) genau aus einem IfDo(sel=konst, body)
+    besteht (optional gefolgt von reinem Kommentar): (sel, konst, body), sonst None."""
+    real = [n for n in nodes if not isinstance(n, Comment)]
+    if len(real) != 1 or not isinstance(real[0], IfDo):
+        return None
+    disp = _eq_dispatch(real[0].cond)
+    if disp is None:
+        return None
+    return disp[0], disp[1], real[0].body
+
+
+def synth_case_across_networks(networks):
+    """Fasst aufeinanderfolgende REGIONs, die je eine Einzelverteilung auf DENSELBEN
+    Selektor sind, zu einer CASE-REGION zusammen. networks: list[(title, nodes)].
+    Liefert neue Netzwerkliste. REGION-Titel werden zu Branch-Kommentaren."""
+    out = []
+    i = 0
+    n = len(networks)
+    while i < n:
+        title, nodes = networks[i]
+        disp = _region_single_dispatch(nodes)
+        if disp is None:
+            out.append((title, nodes))
+            i += 1
+            continue
+        sel = disp[0]
+        group = []   # (title, const, body)
+        j = i
+        consts_seen = set()
+        while j < n:
+            d = _region_single_dispatch(networks[j][1])
+            if d is None or d[0] != sel or d[1] in consts_seen:
+                break
+            consts_seen.add(d[1])
+            group.append((networks[j][0], d[1], d[2]))
+            j += 1
+        if len(group) < 2:
+            out.append((title, nodes))
+            i += 1
+            continue
+        branches = []
+        for gtitle, const, body in group:
+            b = list(body)
+            if b and isinstance(b[-1], Return):
+                b = b[:-1]
+            key = _body_key(b)
+            for lab in branches:
+                if lab[2] == key and lab[3] == gtitle:
+                    lab[0].append(const)
+                    break
+            else:
+                branches.append([[const], b, key, gtitle])
+        case_branches = [(labs, body, gtitle) for labs, body, _, gtitle in branches]
+        out.append((f"CASE {sel}", [Case(sel, case_branches)]))
+        i = j
+    return out