@Override
	public String getSingleFormalExpression() {
		//filter the redundant elements
		if(!this.getRemark().equals(InfoEnum.ElementRemark.NORMAL.name())){
			return "";
		}
		
		String expression = null;
		switch (InfoEnum.RequirementElementType.valueOf(this.getType())){
			case ACTOR:
				expression = "actor("+this.getFormalName()+").";
				break;
			case GOAL:
				expression = "goal("+this.getFormalName()+").";
				break;
			case TASK:
				expression = "task("+this.getFormalName()+").";
				break;
			case SOFTGOAL:
				expression = "softgoal("+this.getFormalName()+").";
				break;
			case DOMAIN_ASSUMPTION:
				expression = "d_assumption("+this.getFormalName()+").";
				break;
			case QUALITY_CONSTRAINT:
				expression = "q_constraint("+this.getFormalName()+").";
				break;
			case SECURITY_GOAL:
				// remove "(S)"
				expression = "sec_goal("+this.getFormalName()+").";
				break;
			case SECURITY_MECHANISM:
				// remove "(S)"
				expression = "sec_mechanism("+this.getFormalName()+").";
				break;
			default:
				expression = "";
				break;
		}
		
//		expression = expression.replaceAll(" ", "_");
		return expression;//.toLowerCase();
	}