must be shown that a person skilled in the art would be able to take this particular step in innovation. Beloit Canada Ltd. et al. v. Valmet Oy defines the person skilled in the art as a: "technician skilled in the art but having no scintilla of inventiveness or imagination; a paragon of deduction and dexterity, wholly devoid of intuition; a triumph of the left hemisphere over the right. The question to be asked is whether this mythical creature [...] would, in the light of the state of the art and of common general knowledge as at the claimed date of invention, have come directly and without difficulty to the solution taught by the patent". The current approach used in Canadian patent law was enunciated by the Supreme Court of Canada in Apotex Inc. v. Sanofi‑Synthelabo Canada Inc. In coming to its decision, a court must consider: The notional person skilled in the art and that person's relevant common knowledge; The inventive concept of the claim must be determined and construed; Any differences that exist between the art prior to the claim and the inventive concept of the claim; Whether these differences constitute steps which would be obvious to the person skilled in the art, without knowledge of the invention. In some fields, experimentation is common and some experiments are considered to be "obvious-to-try". Apotex Inc. v. Sanofi‑Synthelabo Canada Inc. outlines major considerations in fields where this occurs: whether it is self-evident that what is being tried should work, the extent of the effort required to achieve the invention, and motive in the prior art to find a solution to the problem. In some cases, this could lead to a finding that the additional step taken was obvious and therefore the patent for the additional innovation will be considered void. Non-infringement defences A defendant in a patent infringement case can also argue that while the plaintiff's patent is valid, they have not infringed the patent. Under section 42 of the Canadian Patent Act, a patent holder has the exclusive right, liberty and privilege to make, construct, sell and use the invention for the duration of the patent. A defence based on these terms would typically focuses on use, which has been given special attention due to the difficulty of interpreting the term "use". Use has been defined in Monsanto Canada Inc. v. Schmeiser as any activity that deprives an inventor,