I fixed something that was broken. The n modifier on a W or F step, which is not useful in the normal meaning of non-jumping, was 'overloaded', and supposed to indicate that the step 'leaves behind' an e.p. square on the square it came from. This way the path of lame leapers explicitly specified as a multi-leg move could precisely indicate whether and where the piece could be e.p. captured.
The Diagram furthermore applies the rule that royals can be e.p. captured by normal capture (c) moves; the capturing piece does not need to have an explicit e mode for that, like it would need to e.p. capture non-royal pieces. This is for instance how the ban on castling out of or through check works: the castling creates e.p. squares on the King's origin, and the square it passes through. So that castling through check exposes the King to e.p. capture, and would thus be illegal.
I used this to make a Diagram for Caissa Brittania, where the royal Queen cannot move through check (nQ). Each step in the slide then created an e.p. square. But also on the origin, which would forbid moving out of check. But in Caissa Brittania moving out of check is allowed, so I suppressed generation of an e.p. square on the origin, and only left it for later steps in the slide.
This, however, broke the use of n on non-sliding W or F, where it became a complete no-op. I now fixed this. So nK would now be a King that cannot move out of check without getting e.p. captured, but moving a royal nQ out of check would still be legal.
[Edit] I am now starting to doubt the wisdom of this (irregularity-introducing) convention. If nQ would also create an e.p. square on the origin, one could still write [K?nQ] (= KyafnK) when this is not desired. OTOH, with the convention you would need [nK?nQ] (= nKnyafnK) for a royal Queen that cannot move out of check. [K?Q] is after all just synonymous for Q, but allows you to tinker the properties of the first step separately from later steps. I suppose that neither of these is particularly more complex than the other. But it bothers me that nW and nR would be treated differently as to moving out of check is concerned.
I fixed something that was broken. The n modifier on a W or F step, which is not useful in the normal meaning of non-jumping, was 'overloaded', and supposed to indicate that the step 'leaves behind' an e.p. square on the square it came from. This way the path of lame leapers explicitly specified as a multi-leg move could precisely indicate whether and where the piece could be e.p. captured.
The Diagram furthermore applies the rule that royals can be e.p. captured by normal capture (c) moves; the capturing piece does not need to have an explicit e mode for that, like it would need to e.p. capture non-royal pieces. This is for instance how the ban on castling out of or through check works: the castling creates e.p. squares on the King's origin, and the square it passes through. So that castling through check exposes the King to e.p. capture, and would thus be illegal.
I used this to make a Diagram for Caissa Brittania, where the royal Queen cannot move through check (nQ). Each step in the slide then created an e.p. square. But also on the origin, which would forbid moving out of check. But in Caissa Brittania moving out of check is allowed, so I suppressed generation of an e.p. square on the origin, and only left it for later steps in the slide.
This, however, broke the use of n on non-sliding W or F, where it became a complete no-op. I now fixed this. So nK would now be a King that cannot move out of check without getting e.p. captured, but moving a royal nQ out of check would still be legal.
[Edit] I am now starting to doubt the wisdom of this (irregularity-introducing) convention. If nQ would also create an e.p. square on the origin, one could still write [K?nQ] (= KyafnK) when this is not desired. OTOH, with the convention you would need [nK?nQ] (= nKnyafnK) for a royal Queen that cannot move out of check. [K?Q] is after all just synonymous for Q, but allows you to tinker the properties of the first step separately from later steps. I suppose that neither of these is particularly more complex than the other. But it bothers me that nW and nR would be treated differently as to moving out of check is concerned.