Apparently I forgot to add the link to the XBetza page in my previous comment; I've now added it there.
yafsF is indeed the sliding part. a is as you've found, ‘again’; fs for w's and F's is interpreted as for a king, so for an F it changes to a W direction — and ‘forward’ for anything but the first part of the move is interpreted as ‘outward’ (like Alfonso about the rhinoceros); y is a ‘range toggle’ i.e. it switches from being a leaper/stepper to being a slider. Thus, yafsF is one step diagonally followed by a 45° turn and sliding orthogonally.
Complexity is in the eye of the beholder. It's not immediately obvious (especially compared to t[FR]) but it's apperntly easier to describe to a computer (and easier to generalise), which for the interactive diagrams is a definite plus
Apparently I forgot to add the link to the XBetza page in my previous comment; I've now added it there.
yafsFis indeed the sliding part.ais as you've found, ‘again’;fsforw's andF's is interpreted as for a king, so for anFit changes to aWdirection — and ‘forward’ for anything but the first part of the move is interpreted as ‘outward’ (like Alfonso about the rhinoceros);yis a ‘range toggle’ i.e. it switches from being a leaper/stepper to being a slider. Thus,yafsFis one step diagonally followed by a 45° turn and sliding orthogonally.Complexity is in the eye of the beholder. It's not immediately obvious (especially compared to
t[FR]) but it's apperntly easier to describe to a computer (and easier to generalise), which for the interactive diagrams is a definite plus