Preprocessor commands are put in braces.

Built-in macros include:
  *  <tt>{+}</tt>
  *  <tt>{-}</tt>
  *  <tt>{*}</tt>
  *
  *  <tt>{mod}</tt>
  *  <tt>{band}</tt>
  *  <tt>{bor}</tt>
  *  <tt>{bxor}</tt>
  *  <tt>{bnot}</tt>
  *  <tt>{bit}</tt>
  *  <tt>{cat}</tt>
  *  <tt>{version}</tt>
  *  <tt>{define}</tt>
  *  <tt>{include}</tt>
  *  <tt>{call}</tt>

<h2>Computational class</h2>
It is believed to be Turing-complete, because a system] can be implemented, for example:
<verbatim-1>
{define "skip" {call \2}}
{define "1" {skip \1|"3"|"3"|"2"|"1"|"H"}}
{define "2" {skip \1|"3"|"3"|"1"}}
{define "3" {skip \1|"3"|"3"}}
{define "H" \1}
{call "2"|"1"|"1"}
</verbatim-1>