nginx: [emerg] "let" directive is not allowed here

[root-wyj]

let不能再if中执行。(let directive is not allowed in if body)

        location /let {

            if ($uri ~ ^/let/(\d+)$) {
                echo $uri;
                set $id $1;
                echo $id;
                let $dived ( 3 / 2 );
                echo $dived
            }
        }

检查配置文件的时候 会不通过，报题目那样的错误