theorem
  p <X> |[ 0,0,0 ]| = |[ 0,0,0 ]|
proof
  thus p <X> |[ 0,0,0 ]|
  = |[ (p.2 * 0)-(p.3 * 0),(p.3 * 0)-(p.1 * 0),(p.1 * 0)-(p.2 * 0) ]|
  .= |[ 0,0,0 ]|;
end;
