Hi, is there anyone can tell me what does the ::= mean?<div>And what does the code below mean?<br><div><p style="margin: 0.0px 0.0px 0.0px 0.0px; font: 10.0px Helvetica">expr<span style="font: 12.0px Helvetica"> </span>::=<span style="font: 12.0px Helvetica"> </span>expr addop term<span style="font: 12.0px Helvetica"> <span class="Apple-style-span" style="font-size: 10px; ">|<span style="font: 12.0px Helvetica"> </span>term</span></span></p>
<div>Thank you in advance!</div></div></div>