diff --git a/.DS_Store b/.DS_Store
index bdc8bd790..e4d2716c0 100644
Binary files a/.DS_Store and b/.DS_Store differ
diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 23658c414..0df38c074 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -20,6 +20,9 @@ jobs:
         python -m pip install --upgrade pip
         pip install -r requirements.txt
 
+    - name: Generate antlr4 dependencies
+      run: antlr4 -Dlanguage=Python3 -Xexact-output-dir project/lang.g4 -o project/lang
+
     - name: Run tests
       run: |
         python scripts/run_tests.py
diff --git a/.gitignore b/.gitignore
index 91c4207d9..27fa252ac 100644
--- a/.gitignore
+++ b/.gitignore
@@ -104,6 +104,7 @@ celerybeat.pid
 # Environments
 .env
 .venv
+project/lang
 env/
 venv/
 ENV/
diff --git a/project/lang.g4 b/project/lang.g4
new file mode 100644
index 000000000..d95c3ef98
--- /dev/null
+++ b/project/lang.g4
@@ -0,0 +1,36 @@
+grammar lang;
+
+WS: [ \r\n\t]+ -> skip;
+
+prog: stmt* EOF;
+
+stmt: bind | add | remove | declare;
+
+declare: 'let' VAR 'is' 'graph';
+bind: 'let' VAR '=' expr;
+remove: 'remove' ('vertex' | 'edge' | 'vertices') expr 'from' VAR;
+add: 'add' ('vertex'|'edge') expr 'to' VAR;
+
+
+expr: NUM | CHAR | VAR | edge_expr | set_expr | regexp | select;
+
+set_expr: '[' expr (',' expr)* ']';
+edge_expr: '(' expr ',' expr ',' expr ')';
+regexp:
+        CHAR
+        | VAR
+        | '(' regexp ')'
+        | regexp '|' regexp
+        | regexp '^' range
+        | regexp '.' regexp
+        | regexp '&' regexp;
+
+range: '[' NUM '..' NUM? ']';
+select: v_filter? v_filter? 'return' VAR (',' VAR)? 'where' VAR 'reachable'
+        'from' VAR 'in' VAR 'by' expr;
+
+v_filter: 'for' VAR 'in' expr;
+
+VAR: [a-z] [a-z0-9]*;
+NUM: '0' | ([1-9] [0-9]*);
+CHAR: '"' [a-z] '"';
diff --git a/project/task11.py b/project/task11.py
new file mode 100644
index 000000000..600ac7b2b
--- /dev/null
+++ b/project/task11.py
@@ -0,0 +1,49 @@
+from project.lang.langLexer import langLexer
+from project.lang.langParser import langParser
+from project.lang.langListener import langListener
+
+from antlr4 import ParserRuleContext, CommonTokenStream
+from antlr4.InputStream import InputStream
+
+
+class NodeCountListener(langListener):
+
+    def __init__(self) -> None:
+        super(langListener, self).__init__()
+        self.count = 0
+
+    def enterEveryRule(self, ctx):
+        self.count += 1
+
+    def get_count(self):
+        return self.count
+
+
+class StringifyListener(langListener):
+
+    def __init__(self):
+        super(langListener, self).__init__()
+        self.result = ""
+
+    def enterEveryRule(self, rule):
+        self.result += rule.getText()
+
+    def get_result(self):
+        return self.result
+
+
+def prog_to_tree(program: str) -> tuple[ParserRuleContext, bool]:
+    parser = langParser(CommonTokenStream(langLexer(InputStream(program))))
+    return parser.prog(), (parser.getNumberOfSyntaxErrors() == 0)
+
+
+def nodes_count(tree: ParserRuleContext) -> int:
+    listener = NodeCountListener()
+    tree.enterRule(listener)
+    return listener.get_count()
+
+
+def tree_to_prog(tree: ParserRuleContext) -> str:
+    listener = StringifyListener()
+    tree.enterRule(listener)
+    return listener.get_result()
diff --git a/project/task7.py b/project/task7.py
index badd17b3a..fa2f70a95 100644
--- a/project/task7.py
+++ b/project/task7.py
@@ -53,7 +53,7 @@ def cfpq_with_matrix(
                 (p.body[0].to_text(), p.body[1].to_text())
             )
 
-    for i in range(graph.number_of_nodes() ** 2):
+    for j in range(graph.number_of_nodes() ** 2):
         for N, NN in N_to_NN.items():
             for Nl, Nr in NN:
                 M_new[N] += M[Nl] @ M[Nr]
diff --git a/requirements.txt b/requirements.txt
index 04c4f5c00..bf66ffb80 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,4 +1,5 @@
 antlr4-python3-runtime
+antlr4-tools
 black
 cfpq-data
 grammarinator @ git+https://github.com/renatahodovan/grammarinator.git@f3ffa71
diff --git a/tests/.DS_Store b/tests/.DS_Store
index cc2d7b888..67aada108 100644
Binary files a/tests/.DS_Store and b/tests/.DS_Store differ
diff --git a/tests/autotests/.DS_Store b/tests/autotests/.DS_Store
new file mode 100644
index 000000000..5ec935225
Binary files /dev/null and b/tests/autotests/.DS_Store differ
diff --git a/tests/test_task_1.py b/tests/test_task_1.py
deleted file mode 100644
index 5e3adb92f..000000000
--- a/tests/test_task_1.py
+++ /dev/null
@@ -1,35 +0,0 @@
-import networkx as nx
-import os
-import tempfile
-import pytest
-from project import create_labeled_two_cycle_graph, graph_info
-
-
-@pytest.fixture()
-def start():
-    print("Start test")
-
-
-def test_create_labeled_two_cycle_graph():
-    with tempfile.NamedTemporaryFile(suffix=".dot") as tmp_file:
-        create_labeled_two_cycle_graph(3, 4, ("a", "b"), tmp_file.name)
-        assert os.path.exists(tmp_file.name)
-
-        G = nx.drawing.nx_pydot.read_dot(tmp_file.name)
-
-        assert G.number_of_nodes() == 8
-        assert G.number_of_edges() == 9
-        for _, _, data in G.edges(data=True):
-            assert data["label"] in ["a", "b"]
-
-
-def test_graph_info():
-    G = nx.Graph()
-    G.add_nodes_from([1, 2, 3])
-    G.add_edges_from([(1, 2, {"label": "a"}), (2, 3, {"label": "b"})])
-
-    node_count, edge_count, labels = graph_info(G)
-
-    assert node_count == 3
-    assert edge_count == 2
-    assert labels == {"a", "b"}