code: public static Pattern modifiedPESimple()
  	{
  		Pattern p = new Pattern(EntityReference.class, "modified ER");
  		p.add(erToPE(), "modified ER", "first PE");
  		p.add(participatesInConv(), "first PE", "Conversion");
  		p.add(new ConversionSide(ConversionSide.Type.OTHER_SIDE), "first PE", "Conversion", "second PE");
  		p.add(equal(false), "first PE", "second PE");
  		p.add(peToER(), "second PE", "modified ER");
  		return p;
  	}
docs: Pattern for an EntityReference has distinct PhysicalEntities associated with both left and
  right of a Conversion.
  @return the pattern