diff --git a/liquidjava-verifier/.vscode/settings.json b/liquidjava-verifier/.vscode/settings.json
new file mode 100644
index 00000000..385f27a2
--- /dev/null
+++ b/liquidjava-verifier/.vscode/settings.json
@@ -0,0 +1,3 @@
+{
+  "java.configuration.updateBuildConfiguration": "interactive"
+}
diff --git a/liquidjava-verifier/pom.xml b/liquidjava-verifier/pom.xml
index 5b42f4cb..919efbb0 100644
--- a/liquidjava-verifier/pom.xml
+++ b/liquidjava-verifier/pom.xml
@@ -95,6 +95,46 @@
 					</execution>
 				</executions>
 			</plugin>
+			
+			<plugin>
+                <groupId>org.jacoco</groupId>
+                <artifactId>jacoco-maven-plugin</artifactId>
+                <version>0.8.14</version>
+                <executions>
+                    <execution>
+                        <id>default-prepare-agent</id>
+                        <goals>
+                            <goal>prepare-agent</goal>
+                        </goals>
+                    </execution>
+                    <execution>
+                        <id>default-report</id>
+                        <goals>
+                            <goal>report</goal>
+                        </goals>
+                    </execution>
+                    <execution>
+                        <id>default-check</id>
+                        <goals>
+                            <goal>check</goal>
+                        </goals>
+                        <configuration>
+                            <rules>
+                                <rule>
+                                    <element>BUNDLE</element>
+                                    <limits>
+                                        <limit>
+                                            <counter>COMPLEXITY</counter>
+                                            <value>COVEREDRATIO</value>
+                                            <minimum>0.60</minimum>
+                                        </limit>
+                                    </limits>
+                                </rule>
+                            </rules>
+                        </configuration>
+                    </execution>
+                </executions>
+            </plugin>
 		</plugins>
 	</build>
 
diff --git a/liquidjava-verifier/src/test/java/liquidjava/ast/opt/TestOptimization.java b/liquidjava-verifier/src/test/java/liquidjava/ast/opt/TestOptimization.java
new file mode 100644
index 00000000..d32a94bc
--- /dev/null
+++ b/liquidjava-verifier/src/test/java/liquidjava/ast/opt/TestOptimization.java
@@ -0,0 +1,20 @@
+package liquidjava.ast.opt;
+
+import static org.junit.Assert.assertEquals;
+
+import org.junit.Test;
+
+import liquidjava.rj_language.ast.BinaryExpression;
+import liquidjava.rj_language.ast.LiteralInt;
+import liquidjava.rj_language.opt.ConstantFolding;
+import liquidjava.rj_language.opt.derivation_node.ValDerivationNode;
+
+public class TestOptimization {
+    @Test
+    public void testBinaryFold() {
+        BinaryExpression b = new BinaryExpression(new LiteralInt(1), "+", new LiteralInt(2));
+
+        ValDerivationNode r = ConstantFolding.fold(new ValDerivationNode(b, null));
+        assertEquals(r.getValue(), new LiteralInt(3));
+    }
+}
diff --git a/liquidjava-verifier/src/test/java/liquidjava/ast/opt/TestOptimizationIntegration.java b/liquidjava-verifier/src/test/java/liquidjava/ast/opt/TestOptimizationIntegration.java
new file mode 100644
index 00000000..1545408e
--- /dev/null
+++ b/liquidjava-verifier/src/test/java/liquidjava/ast/opt/TestOptimizationIntegration.java
@@ -0,0 +1,22 @@
+package liquidjava.ast.opt;
+
+import static org.junit.Assert.assertEquals;
+
+import org.junit.Test;
+
+import liquidjava.rj_language.ast.BinaryExpression;
+import liquidjava.rj_language.ast.LiteralInt;
+import liquidjava.rj_language.opt.ConstantFolding;
+import liquidjava.rj_language.opt.derivation_node.ValDerivationNode;
+
+public class TestOptimizationIntegration {
+    @Test
+    public void testBinaryFoldNested() {
+        BinaryExpression inner = new BinaryExpression(new LiteralInt(2), "+", new LiteralInt(3));
+        BinaryExpression outer = new BinaryExpression(new LiteralInt(1), "+", inner);
+        ValDerivationNode r = ConstantFolding.fold(new ValDerivationNode(outer, null));
+        assertEquals(new LiteralInt(6), r.getValue());
+    }
+}
+
+// António Rebelo - 58530
\ No newline at end of file
diff --git a/liquidjava-verifier/src/test/java/liquidjava/rj_language/TestLiteralString.java b/liquidjava-verifier/src/test/java/liquidjava/rj_language/TestLiteralString.java
new file mode 100644
index 00000000..25906763
--- /dev/null
+++ b/liquidjava-verifier/src/test/java/liquidjava/rj_language/TestLiteralString.java
@@ -0,0 +1,19 @@
+
+package liquidjava.rj_language;
+
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNotEquals;
+import static org.junit.Assert.assertTrue;
+
+import org.junit.Test;
+import liquidjava.rj_language.ast.LiteralString;
+
+public class TestLiteralString {
+    // Teste fornecido
+    @Test
+    public void testLiteralString() {
+        LiteralString s1 = new LiteralString("hello");
+        LiteralString s2 = new LiteralString("world");
+        assertNotEquals(s1.hashCode(), s2.hashCode());
+    }
+}
diff --git a/liquidjava-verifier/src/test/java/liquidjava/rj_language/TestLiteralStringEquals.java b/liquidjava-verifier/src/test/java/liquidjava/rj_language/TestLiteralStringEquals.java
new file mode 100644
index 00000000..d3e9324c
--- /dev/null
+++ b/liquidjava-verifier/src/test/java/liquidjava/rj_language/TestLiteralStringEquals.java
@@ -0,0 +1,33 @@
+package liquidjava.rj_language;
+
+import static org.junit.Assert.*;
+import org.junit.Test;
+import liquidjava.rj_language.ast.LiteralString;
+
+public class TestLiteralStringEquals {
+    @Test
+    public void testBothValuesNull() {
+        LiteralString a = new LiteralString(null);
+        LiteralString b = new LiteralString(null);
+        assertTrue(a.equals(b));
+        assertTrue(b.equals(a));
+        assertTrue(a.equals(a));
+        assertEquals(a.hashCode(), b.hashCode());
+    }
+
+    @Test
+    public void testThisValueNullOtherNotNull() {
+        LiteralString a = new LiteralString(null);
+        LiteralString b = new LiteralString("hello");
+        assertFalse(a.equals(b));
+        assertFalse(b.equals(a));
+    }
+
+    @Test
+    public void testOtherValueNullThisNotNull() {
+        LiteralString a = new LiteralString("hello");
+        LiteralString b = new LiteralString(null);
+        assertFalse(a.equals(b));
+        assertFalse(b.equals(a));
+    }
+}
\ No newline at end of file