"△" indicates an operation symbol, its meaning is: a△b=2a-b, if x△(2△3)=3, then x=what
"△"表示一种运算符号，其意义是：a△b=2a-b，如果x△(2△3)=3，则x=多少
<gadget id="calculator">1 + 1</gadget>
<output>2</output>

<result>2</result>