+h3 En-passant capture
+
+p.
+ Capturing en-passant is allowed under certain conditions.
+ If the opponent moved a pawn allowing such a capture (once or twice),
+ then (to take it) you must capture en-passant at the first move of your turn.
+ After that, if (and only if) there is another en-passant capture available
+ you can play it on the second move.
+
+p.
+ Note: if a pawn 2-squares jump was made and then a piece landed at the
+ en-passant square at the second move, a pawn capture on this square
+ takes only the piece.
+ And, if a pawn advanced twice then en-passant capture
+ on its first movement is impossible (the pawn is now "too far").
+