Keys "s"=save "l"=load "b"=back once
Robert Shimmin, 2003. "A threat to capture the opponent's king does not give check if it opens one's own king to immediate recapture." You can escape check by checking the opposing king. A king may move adjacent to an opposing king if in this situation the moving king is defended but not otherwise attacked. The king cannot check a defended king.
These are simple illustrations rather than strong opponents.
Bug reports? -- Thank you! Keep them coming!