Also this: http://research.microsoft.com/en-us/um/people/leino/puzzles.html http://research.microsoft.com/en-us/um/people/leino/puzzles.... Does anyone know of

Also this: http://research.microsoft.com/en-us/um/people/leino/puzzles.html http://research.microsoft.com/en-us/um/people/leino/puzzles.... Does anyone know of any good books with these kinds of problems?