Provided that △ is a symbol of operation, and a△b=ab-ba, try to calculate the value of 4△(3△2).
规定△是一种运算符号，且a△b=ab-ba，试计算4△(3△2)的值．
<gadget id="calculator">4 ** 1</gadget>
<output>4</output>

<gadget id="calculator">1 ** 4</gadget>
<output>1</output>

<gadget id="calculator">4 - 1</gadget>
<output>3</output>

<result>3</result>