Extending the mosaicking metaphor may provide a useful illustration of this point. A mosaic, in its literal sense, is a piece of decorative art made by assembling small pieces of material such as beads, glass, stone, shells and tiles. Imagine a situation where there are many different boxes of material, each box containing many different types of material in many different sizes and quantities. At trial, the defendant will try to prove, often with the aid of expert evidence, that an unimaginative person will pick certain specific pieces from certain specific boxes and combine them in certain specific ways, so as to form an image that is similar to that claimed by the patent. The defendant does not have to provide particulars to prove all of these at the pleadings stage. However, he has to do more than simply listing the boxes and asserting that an unimaginative person assembling certain unspecified combinations of certain unspecified pieces from certain unspecified boxes will somehow form the image in question. Otherwise, the plaintiff will potentially have to engage experts to pore over all the pieces in all the boxes, coming up with all possible combinations that might be relied on at trial, so as to determine how and whether he will contest each unique combination. This would likely be a massively expensive and time-consuming process. As such, at the pleadings stage, a defendant should minimally provide an indication of the combinations he intends to rely on, so that the plaintiff has a broad idea of the issues that he will have to deal with at trial and be able to direct his preparations accordingly.