H. G. Muller wrote on Wed, Nov 13, 2019 10:47 PM UTC:
I implemented a new enhancement of XBetza notation in XBoard, to be able to more precisely indicate generation of e.p. rights on oblique moves. 'Non-jumping' is an ill-defined concept for those; nN could be a Mao or a Moa, so with the existing convention ifmnN would not sufficiently specify what the blocking square (and thus e.p. square) is. For that a multi-leg description fully specifying the path is necessary, like mafsW for the Mao.
XBetza uses the 'e' modifier to indicate e.p. capture, as alternative to the 'm' and 'c' modality. But this only seems useful in the final leg of a muti-leg move. So I redefined the meaning of 'e' in a non-final leg to me an 'm' move that generates e.p. rights on its target square. This would make the double-push of a FIDE Pawn ifeafmW. (And its e.p. capture feF, which can combine with the normal capture to fceF.)
[Edit] On thecond thoughts I wonder if it wouldn't be better to use the 'n' modifier instead of 'e' for indicating generation of e.p. rights by a non-final leg, and reserve the latter for actual capture. When laying out a lame-leaper trajectory one will almost certainly use a stepper atom (W, F or K), and 'n' can never have its traditional non-jumping meaning there. OTOH, e.p. capture on a non-final leg is not completely out of the question: one could want to define an e.p.-capturing Checker, feafmF, where the 'e' on the non-final leg then means that leg should end on the e.p. square (by definition empty), and that the move as a whole leads to removal of the previously moved piece as a side effect. Double-push FIDE would then become ifnafmW to generate e.p. rights.
I implemented a new enhancement of XBetza notation in XBoard, to be able to more precisely indicate generation of e.p. rights on oblique moves. 'Non-jumping' is an ill-defined concept for those; nN could be a Mao or a Moa, so with the existing convention ifmnN would not sufficiently specify what the blocking square (and thus e.p. square) is. For that a multi-leg description fully specifying the path is necessary, like mafsW for the Mao.
XBetza uses the 'e' modifier to indicate e.p. capture, as alternative to the 'm' and 'c' modality. But this only seems useful in the final leg of a muti-leg move. So I redefined the meaning of 'e' in a non-final leg to me an 'm' move that generates e.p. rights on its target square. This would make the double-push of a FIDE Pawn ifeafmW. (And its e.p. capture feF, which can combine with the normal capture to fceF.)
[Edit] On thecond thoughts I wonder if it wouldn't be better to use the 'n' modifier instead of 'e' for indicating generation of e.p. rights by a non-final leg, and reserve the latter for actual capture. When laying out a lame-leaper trajectory one will almost certainly use a stepper atom (W, F or K), and 'n' can never have its traditional non-jumping meaning there. OTOH, e.p. capture on a non-final leg is not completely out of the question: one could want to define an e.p.-capturing Checker, feafmF, where the 'e' on the non-final leg then means that leg should end on the e.p. square (by definition empty), and that the move as a whole leads to removal of the previously moved piece as a side effect. Double-push FIDE would then become ifnafmW to generate e.p. rights.