protected boolean isDiggableRoom(final Room R)
	{
		if(R==null)
			return false;
		if(((R.domainType()&Room.INDOORS)>0)
		&&(R.domainType()!=Room.DOMAIN_INDOORS_CAVE)
		&&((R.getAtmosphere()&RawMaterial.MATERIAL_ROCK)==0))
			return false;
		if((R.domainType()==Room.DOMAIN_OUTDOORS_CITY)
		   ||(R.domainType()==Room.DOMAIN_OUTDOORS_SPACEPORT)
		   ||(R.domainType()==Room.DOMAIN_OUTDOORS_UNDERWATER)
		   ||(R.domainType()==Room.DOMAIN_OUTDOORS_AIR)
		   ||(R.domainType()==Room.DOMAIN_OUTDOORS_WATERSURFACE))
			return false;
		return true;
	}