diff --git a/AlgebraicDataflowArchitectureModel/src/code/ast/NumberLiteral.java b/AlgebraicDataflowArchitectureModel/src/code/ast/NumberLiteral.java
index ac75f20..a437c0a 100644
--- a/AlgebraicDataflowArchitectureModel/src/code/ast/NumberLiteral.java
+++ b/AlgebraicDataflowArchitectureModel/src/code/ast/NumberLiteral.java
@@ -47,9 +47,7 @@
 			throw new IllegalArgumentException("Token value must not be empty.");
 		}
 		
-		// TODO: 0 check
-		
-		if (NumberUtil.isBinaryNumber(tokenValue) || NumberUtil.isOctalNumber(tokenValue) || NumberUtil.isHexNumber(tokenValue)) {
+		if (NumberUtil.isDecimalNumber(tokenValue) || NumberUtil.isBinaryNumber(tokenValue) || NumberUtil.isOctalNumber(tokenValue) || NumberUtil.isHexNumber(tokenValue)) {
 			this.tokenValue = tokenValue;
 		} else {
 			throw new IllegalArgumentException("Invalid number literal: " + tokenValue);
diff --git a/AlgebraicDataflowArchitectureModel/src/code/ast/NumberUtil.java b/AlgebraicDataflowArchitectureModel/src/code/ast/NumberUtil.java
index 0daea7d..4137a35 100644
--- a/AlgebraicDataflowArchitectureModel/src/code/ast/NumberUtil.java
+++ b/AlgebraicDataflowArchitectureModel/src/code/ast/NumberUtil.java
@@ -145,6 +145,25 @@
 		return true;
 	}
 	
+	public static boolean isDecimalNumber(String token) {
+		if (token == null || token.isBlank()) {
+			return false;
+		}
+		
+		// Multiples dots are not allowed
+		String[] tokens = token.split("\\.", -1);
+		if (tokens.length > 2) {
+			return false;
+		}
+		
+		Lexer integerPart = new Lexer(tokens[0].toLowerCase());
+		Lexer fractionalPart = new Lexer(tokens[1].toLowerCase());
+		
+		// TODO: Implement validation logic
+		
+		return true;
+	}
+	
 	/**
 	 * Determines whether the given string is a valid hexadecimal number.
 	 * A valid hexadecimal number starts with "0x" or "0X", followed by a