diff --git a/src/main/java/edu/kit/typicalc/model/TypeInfererLet.java b/src/main/java/edu/kit/typicalc/model/TypeInfererLet.java
index 5614144..eafe6e7 100644
--- a/src/main/java/edu/kit/typicalc/model/TypeInfererLet.java
+++ b/src/main/java/edu/kit/typicalc/model/TypeInfererLet.java
@@ -10,7 +10,8 @@ import java.util.*;
 
 /**
  * Instances of this implementation of TypeInfererInterface are used to execute the sub-inference starting in let steps.
- * They provide an extended constructor to make sure this sub-inference is consistent with the "outer" inference.
+ * They provide an extended constructor (compared to the standard type inferer) to make sure this sub-inference
+ * is consistent with the "outer" inference.
  */
 public class TypeInfererLet implements TypeInfererInterface {
 
@@ -20,6 +21,8 @@ public class TypeInfererLet implements TypeInfererInterface {
 
     /**
      * Initializes a new TypeInfererLet for the given type assumptions, lambda term and type variable factory.
+     * The inference step structure, unification steps, the most general unifier and the
+     * final type are generated and calculated here.
      *
      * @param lambdaTerm      the lambda term to generate the tree for
      * @param typeAssumptions the type assumptions to consider when generating the tree
diff --git a/src/main/java/edu/kit/typicalc/presenter/package-info.java b/src/main/java/edu/kit/typicalc/presenter/package-info.java
new file mode 100644
index 0000000..f3e731a
--- /dev/null
+++ b/src/main/java/edu/kit/typicalc/presenter/package-info.java
@@ -0,0 +1,10 @@
+/**
+ * The presenter connects the model and the view.
+ * It passes the data from the model to the view and the user input from the view to the model.
+ */
+@NonNullFields
+@NonNullApi
+package edu.kit.typicalc.presenter;
+
+import org.springframework.lang.NonNullApi;
+import org.springframework.lang.NonNullFields;
\ No newline at end of file
diff --git a/src/main/java/edu/kit/typicalc/util/package-info.java b/src/main/java/edu/kit/typicalc/util/package-info.java
new file mode 100644
index 0000000..c87488b
--- /dev/null
+++ b/src/main/java/edu/kit/typicalc/util/package-info.java
@@ -0,0 +1,9 @@
+/**
+ * The util package contains classes used in all components of the application.
+ */
+@NonNullFields
+@NonNullApi
+package edu.kit.typicalc.util;
+
+import org.springframework.lang.NonNullApi;
+import org.springframework.lang.NonNullFields;
\ No newline at end of file
diff --git a/src/test/java/edu/kit/typicalc/model/parser/TypeAssumptionParserTest.java b/src/test/java/edu/kit/typicalc/model/parser/TypeAssumptionParserTest.java
index e1074a8..748e782 100644
--- a/src/test/java/edu/kit/typicalc/model/parser/TypeAssumptionParserTest.java
+++ b/src/test/java/edu/kit/typicalc/model/parser/TypeAssumptionParserTest.java
@@ -201,7 +201,8 @@ class TypeAssumptionParserTest {
         tests.put("(x", ParseError.TOO_FEW_TOKENS);
         tests.put("x 11", ParseError.UNEXPECTED_TOKEN.withToken(new Token(Token.TokenType.NUMBER, "11", 2)));
         tests.put("x )", ParseError.UNEXPECTED_TOKEN.withToken(new Token(Token.TokenType.RIGHT_PARENTHESIS, ")", 2)));
-        tests.put("x -> (x) )", ParseError.UNEXPECTED_TOKEN.withToken(new Token(Token.TokenType.RIGHT_PARENTHESIS, ")", 9)));
+        tests.put("x -> (x) )", ParseError.UNEXPECTED_TOKEN
+                .withToken(new Token(Token.TokenType.RIGHT_PARENTHESIS, ")", 9)));
         for (Map.Entry<String, ParseError> entry : tests.entrySet()) {
             TypeAssumptionParser parser = new TypeAssumptionParser();
             Result<Map<VarTerm, TypeAbstraction>, ParseError> type = parser.parse(Map.of("type1", entry.getKey()));