private Tree variableListPro(){
		Tree variable = null;
		VariableList variables = null;
		
		if((variable = variablePro()) != null){
			if(accept(Symbol.Id.PUNCTUATORS,",")!=null){
				if((variables = (VariableList) variableListPro()) != null){
					return new VariableList(variable, variables);
				}
				return null;
			}
			return new VariableList(variable);
			
		}
		
		return null;
	}