A stronger model for peg solitaire, II
  The main problem addressed here is to decide whether it is possible or not to go from a given position on a peg-solitaire board to another one. No non-trivial sufficient conditions are known, but tests have been devised to show impossibility. We expose the way these tests work in a unified formalism and provide a new test which is strictly stronger than all previous ones. 
Olivier Ramar\'e