[basex-talk] Execution problem

Hello, I am executing following query in basex 8.2 let $a := <a>if a > 0 {sum((1,2,3))}</a> return $a o/p : <a>if a > 0 6</a> but when I am executing let $a := <a>if a < 0 {sum((1,2,3))}</a> return $a it gives me a error "Expecting element name , '<' found. Query works for '>' but not with '<'. Thanks Samby