08 May '08 19:48>2 edits
The excelsior problem, posted by SwissGambit, in which a pawn delivers the mate, reminded me of the above composition.
White to play and mate the black king.
1. In the final position the black king must be threatened by a white pawn.
2. White is not allowed to capture any black unit.
3. White is not allowed to lose any of his own units.
This means that wPc2 must somehow reach c6 or c7 without being captured by a black P and without white capturing a black P.