Typically a puzzle problem in BURRTOOLS consists of a collection of pieces (shapes) and a goal, say another shape that the pieces should form when correctly assembled. This is what we call a simple problem definition. Note that it may well be not that 'simple' to solve it in real life. More elaborated or complex puzzle problems contain also colour constraints and/or grouped pieces.
As stated before, a puzzle can be a collection of problems, either simple, complex or a mixture of both. The Puzzle tab (Figure PuzzleTab) provides all the tools needed to build a variety of puzzle problems that are suited for the Solver.