{if 0 || foo}
  foo is not false!
  {if foo}
    OK
  {else}
    WTF? FIXME!!!
  {end}
{else}
  foo is false.
  {if 0 && foo}
    The impossible happened!
  {end}
  {if 1 || 0 }
    You must see this!
  {else}
    ERROR!!!
  {end}
{end}