@Override
	public Node visitThirdPriorExp(ThirdPriorExpContext ctx) {
		String symbol = "";
		if (ctx.GREATERE() != null)
			symbol = ">=";
		if (ctx.LESSE() != null)
			symbol = "<=";
		if (ctx.LESS() != null)
			symbol = "<";
		if (ctx.GREATER() != null)
			symbol = ">";
		return new Operation(ctx.start.getLine(), symbol, visit(ctx.expr(0)), visit(ctx.expr(1)));
	}