[Exim] if statement

Is it possible to nest the "AND" / "OR" conditions within each other? The
FAQ doesn't say anything about it and the documentation doesn't say it can
or can't be done. I'm currently using exim from debian slink (2.05-1)

Ie:

${if or {{eq {$local_part}{some name}}
         {and {match {$h_X-ThisHeader:}{something}}
              {match {$h_X-ThatHeader:}{something else}}
         }
        }
  {true} {false}
 }

If not, that explains the error I'm getting.
Please respond.