/* @ pure */ public boolean isCornerField(Coordinate coord) {
		boolean result = false;
		int index = coord.getIndex();
		if (index == index(0, 0) || index == index(0, DIM - 1) || 
				index == index(DIM - 1, 0) || index == index(DIM - 1, DIM - 1)) {
			result = true;
		}
		return result;
	}