diff --git a/.vscode/settings.json b/.vscode/settings.json
index b266fd8..9bd06c2 100644
--- a/.vscode/settings.json
+++ b/.vscode/settings.json
@@ -1,7 +1,4 @@
 {
-    "java.configuration.updateBuildConfiguration": "interactive",
-    "cSpell.words": [
-        "symb"
-    ],
+    "java.configuration.updateBuildConfiguration": "automatic",
     "java.debug.settings.onBuildFailureProceed": true
 }
\ No newline at end of file
diff --git a/latte/pom.xml b/latte/pom.xml
index 4ccd60e..a623f2a 100644
--- a/latte/pom.xml
+++ b/latte/pom.xml
@@ -96,10 +96,14 @@
       <version>${version.spoon}</version>
     </dependency>
 
+		<dependency>
+			<groupId>org.antlr</groupId>
+			<artifactId>antlr4-runtime</artifactId>
+			<version>4.13.2</version>
+		</dependency>
   </dependencies>
 
   <build>
-    <pluginManagement>
       <plugins>
         <plugin>
           <artifactId>maven-clean-plugin</artifactId>
@@ -137,7 +141,18 @@
           <artifactId>maven-project-info-reports-plugin</artifactId>
           <version>3.0.0</version>
         </plugin>
+        <plugin>
+          <groupId>org.antlr</groupId>
+          <artifactId>antlr4-maven-plugin</artifactId>
+          <version>4.13.2</version>
+          <executions>
+            <execution>
+              <goals>
+                <goal>antlr4</goal>
+              </goals>
+            </execution>
+          </executions>
+        </plugin>
       </plugins>
-    </pluginManagement>
   </build>
 </project>
diff --git a/latte/src/main/antlr4/rj/grammar/RJ.g4 b/latte/src/main/antlr4/rj/grammar/RJ.g4
new file mode 100644
index 0000000..094dd9f
--- /dev/null
+++ b/latte/src/main/antlr4/rj/grammar/RJ.g4
@@ -0,0 +1,81 @@
+grammar RJ;
+
+prog: expression EOF;
+
+expression: logicalOrExp;
+
+logicalOrExp
+	: logicalAndExp (OR logicalAndExp)*
+	;
+
+logicalAndExp
+	: equalityExp (AND equalityExp)*
+	;
+
+equalityExp
+	: relationalExp ((EQ | NEQ) relationalExp)?
+	;
+
+relationalExp
+	: additiveExp ((LT | GT | LE | GE) additiveExp)?
+	;
+
+additiveExp
+	: unaryExp ((PLUS | MINUS) unaryExp)*
+	;
+
+unaryExp
+	: (NOT | MINUS) unaryExp
+	| primary
+	;
+
+primary
+	: literal
+	| RESULT
+	| oldExp
+	| fieldAccess
+	| ID
+	| LPAREN expression RPAREN
+	;
+
+oldExp
+	: OLD LPAREN fieldAccess RPAREN
+	;
+
+fieldAccess
+	: ID DOT ID
+	;
+
+literal
+	: BOOL
+	| STRING
+	| INT
+	| REAL
+	;
+
+OLD: 'old';
+RESULT: 'result';
+
+AND: '&&';
+OR: '||';
+EQ: '==';
+LE: '<=';
+LT: '<';
+GE: '>=';
+GT: '>';
+PLUS: '+';
+MINUS: '-';
+NEQ: '!=';
+NOT: '!';
+
+LPAREN: '(';
+RPAREN: ')';
+DOT: '.';
+
+BOOL: 'true' | 'false';
+ID: '#'* [a-zA-Z_][a-zA-Z0-9_#]*;
+STRING: '"' (~["])* '"';
+INT: [0-9]+ ('_' [0-9]+)*;
+REAL: ([0-9]+ '.' [0-9]+) | ('.' [0-9]+);
+
+WS: [ \t\n\r]+ -> channel(HIDDEN);