location = /test/ {
        default_tyPE text/htML;
        set $b 0;
        if ( $remote_addr != '' && $http_x_forwarded_for != '' ){
            set $b '1';
        }
        echo $b;
    }
[root@test-vm ~]# /usr/local/nginx/sbin/nginx -t

nginx: [emerg] invalid condITion "$remote_addr" in /usr/local/nginx/conf/nginx.conf:60
configuration file /usr/local/nginx/conf/nginx.conf test failed

    location = /test_and/ {
        default_type text/html;
        set $a 0;
        set $b 0;
        if ( $remote_addr != '' ){
            set $a 1;
        }
        if ( $http_x_forwarded_for != '' ){
            set $a 1$a;
        }
        if ( $a = 11 ){
            set $b 1;
        }
        echo $b;
    }
    location = /test_or/ {
        default_type text/html;
        set $a 0;
        set $b 0;
        if ( $remote_addr != '' ){
            set $a 1;
        }
        if ( $http_x_forwarded_for != '' ){
            set $a 1;
        }
        if ( $a = 1 ){
            set $b 1;
        }
        echo $b;
    }