skew <ncs-strict-skew-statement> end

--{Defines skew frame matrix P, and origin of skew frame O.
   The Bricogne convention is used for the transformation
   i.e. Xskew = P**-1(X + O). The transformation defaults to 
   identity if ncs relationships are defined before the skew.}

<ncs-strict-skew-statement> :==

  <matrix>
  --{Skew matrix.}
  translation <vector>
  --{Translation vector (in angstroms).}