return (OpQuadPattern)op ;
if ( op instanceof OpSequence )
{
// Is last in OpSequence an BGP?
OpSequence opSeq = (OpSequence)op ;
List<Op> x = opSeq.getElements() ;
if ( x.size() > 0 )
{
Op opTop = x.get(x.size()-1) ;
if ( opTop instanceof OpQuadPattern )
return (OpQuadPattern)opTop ;