Doing mathematics in general, and solving mathematics problems in particular, is an activity requiring the individual
to engage in a variety of cognitive actions, each of which requires some knowledge and skill, and some of which are not
routine. There have been many attempts to define and describe problem solving, but most have fallen short of capturing
the sense of what it involves. One shortcoming of most definitions is their failure to acknowledge the essential role
played by representations in the process. The following description comes closer than others we have read