code: public static int borderInverseLower( WlBorderCoef<?> desc, BorderIndex1D border  ) {
  
  		WlCoef inner = desc.getInnerCoefficients();
  		int borderSize = borderForwardLower(inner);
  
  		WlCoef ll = borderSize > 0 ? inner : null;
  		WlCoef lu = ll;
  		WlCoef uu = inner;
  		int indexLU = 0;
  
  		if( desc.getLowerLength() > 0 ) {
  			ll = desc.getBorderCoefficients(0);
  			indexLU = desc.getLowerLength()*2-2;
  			lu = desc.getBorderCoefficients(indexLU);
  		}
  
  		if( desc.getUpperLength() > 0 ) {
  			uu = desc.getBorderCoefficients(-2);
  		}
  
  		border.setLength(2000);
  		borderSize = checkInverseLower(ll,0,border,borderSize);
  		borderSize = checkInverseLower(lu,indexLU,border,borderSize);
  		borderSize = checkInverseLower(uu,1998,border,borderSize);
  
  		return borderSize;
  	}
docs: Returns the lower border for an inverse wavelet transform.