diff --git a/.gitignore b/.gitignore
index cc266fc..37c7e11 100644
--- a/.gitignore
+++ b/.gitignore
@@ -6,3 +6,5 @@
 !/notes
 !/protocol
 !/protocol/*.md
+
+!/code
diff --git a/code/.gitignore b/code/.gitignore
new file mode 100644
index 0000000..bf7b032
--- /dev/null
+++ b/code/.gitignore
@@ -0,0 +1,3 @@
+*
+!/.gitignore
+!/*.py
diff --git a/code/__init__.py b/code/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/code/main.py b/code/main.py
new file mode 100644
index 0000000..f16a6b6
--- /dev/null
+++ b/code/main.py
@@ -0,0 +1,100 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+
+# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+# IMPORTS
+# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+from __future__ import annotations;
+import os;
+import sys;
+sys.tracebacklimit = 0;
+from itertools import product;
+from typing import Dict;
+from typing import Generator;
+from typing import List;
+from typing import Tuple;
+from typing import Union;
+from lark import Tree;
+
+sys.path.insert(0, os.getcwd());
+
+from schema import string_to_parts;
+
+# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+# GLOBAL CONSTANTS
+# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+# zeichenkette = 'A0';
+# zeichenkette = '! A0';
+# zeichenkette = '( A0 && A1 )';
+# zeichenkette = '( A0 || A1 )';
+# zeichenkette = '( A0 -> A1 )';
+zeichenkette = '( A0 -> ((A0 && A3) || ! A2) )';
+# zeichenkette = '(( {G} || !{G} ) -> A5)';
+
+I = ['A0', 'A2'];
+
+# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+# HAUPTVORGANG
+# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+def main():
+    tree = string_to_parts(zeichenkette);
+    print('Syntaxbaum von \033[1m{}\033[0m:\n'.format(zeichenkette));
+    print(tree.pretty());
+    val = rekursiv_eval(tree, I)
+    print('eval(Formel, I) = \033[1m{}\033[0m'.format(val));
+    return;
+
+# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+# SEKUNDÄRVORGÄNGE
+# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+def rekursiv_eval(fml: Tree, I: List[str]) -> bool:
+    if fml.data == 'atom':
+        index = fml.children[0];
+        return 'A{}'.format(index) in I;
+    elif fml.data == 'beliebig':
+        name = fml.children[0];
+        return '{}'.format(name) in I;
+    elif fml.data == 'wahr':
+        return True;
+    elif fml.data == 'falsch':
+        return False;
+    elif fml.data == 'negation':
+        teilformel1 = fml.children[1];
+        if isinstance(teilformel1, Tree):
+            val1 = rekursiv_eval(teilformel1, I);
+            return not val1;
+    elif fml.data == 'konjunktion':
+        teilformel1 = fml.children[0];
+        teilformel2 = fml.children[2];
+        if isinstance(teilformel1, Tree) and isinstance(teilformel2, Tree):
+            val1 = rekursiv_eval(teilformel1, I);
+            val2 = rekursiv_eval(teilformel2, I);
+            return min(val1, val2);
+    elif fml.data == 'disjunktion':
+        teilformel1 = fml.children[0];
+        teilformel2 = fml.children[2];
+        if isinstance(teilformel1, Tree) and isinstance(teilformel2, Tree):
+            val1 = rekursiv_eval(teilformel1, I);
+            val2 = rekursiv_eval(teilformel2, I);
+            return max(val1, val2);
+    elif fml.data == 'implikation':
+        teilformel1 = fml.children[0];
+        teilformel2 = fml.children[2];
+        if isinstance(teilformel1, Tree) and isinstance(teilformel2, Tree):
+            val1 = rekursiv_eval(teilformel1, I);
+            val2 = rekursiv_eval(teilformel2, I);
+            return (val1 <= val2);
+    else:
+        raise Exception('Evaluation nicht möglich!');
+    return True;
+
+# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+# CODE AUSFÜHREN
+# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+if __name__ == '__main__':
+    main();
diff --git a/code/schema.py b/code/schema.py
new file mode 100644
index 0000000..9ebe38d
--- /dev/null
+++ b/code/schema.py
@@ -0,0 +1,64 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+
+# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+# IMPORTS
+# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+from __future__ import annotations;
+import re;
+# install: lark; lark-parser; lark-parser[regex].
+# https://lark-parser.readthedocs.io/en/latest/grammar.html
+from lark import Lark;
+from lark import Tree;
+
+# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+# GLOBAL CONSTANTS
+# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+## lexer
+lexerAussagenlogik = Lark(
+    '''
+    %import common.WS
+    %import common.NUMBER
+    %import common.WORD
+    %ignore WS
+
+    ?start: expr
+
+    ?expr:    atomic | expr_not | expr_and | expr_or | expr_implies
+    ?literal: atomic | "not" atomic
+
+    // atomische Ausdrücke
+    ?atomic:    false | true | atom | generic
+    ?false:     "0"                         -> wahr
+    ?true:      "1"                         -> falsch
+    ?atom:      "A" /[0-9]+/                -> atom
+    ?generic:   "{" /((?!({|})).)+/ "}"     -> beliebig
+
+    // Symbole
+    ?conn_not:  "!"     -> junktor
+    ?conn_and:  /&+/    -> junktor
+    ?conn_or:   /\\|+/  -> junktor
+    ?conn_impl: /->|=>/ -> junktor
+
+    // Junktoren
+    ?expr_not:     conn_not expr                -> negation
+    ?expr_and:     "(" expr conn_or    expr ")" -> konjunktion
+    ?expr_or:      "(" expr conn_and   expr ")" -> disjunktion
+    ?expr_implies: "(" expr conn_impl  expr ")" -> implikation
+    ''',
+    start="expr",
+    regex=True
+);
+
+# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+# MAIN METHOD string -> parts
+# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+def string_to_parts(u: str) -> Tree:
+    try:
+        u_lexed = lexerAussagenlogik.parse(u);
+        return u_lexed;
+    except:
+        raise Exception('Ausdruck \033[1m{}\033[0m konnte nicht erkannt werden!'.format(u));