The case concerns the analysis of obviousness, when the prior art teaches structurally and functionally similar chemical compounds, proving a definite range and variables for a solution of stability.  The Appeal Court held that prior art ranges for solutions of structurally and functionally similar compounds that overlap with a claimed range can establish a prima facie case of obviousness. If one of the predictable solutions leads to an anticipated success, the outcome was obvious to try. The Court also held that there is no requirement that for a variable to be obvious to try, it must be the first variable a person of skill would alter.