I did know about Betza's t[FR] proposal for Griffon, but I had never seen this z(FW) notation. XBetza is only upward compatible with the Betza notation for simple ('single leg') moves, and has its own system for combining these to multi-leg moves, which is more general than any of the suggestions that Betza coined in various scattered places.
The z modifier applied to a slider atom is original Betza notation for a crooked version of the piece, and is still supported in XBetza. On a leaper, such as zW, it never had any meaning.
The role of parentheses has completely changed; in XBeza these indicate zero or more repetitions of the enclosed group. So z(FW) would mean zzFWzFWFWzFWFWFW..., which doesn't really mean anything.
Brackets originally were not used in XBetza, but legs of a move were 'chained' by using an a as separator between the modifiers of each leg. This does the job of unambiguously defining very complex moves, but often leads to a very obfuscated description unsuitable for human digestion. A much clearer notation is possible by using brackets (but in a way that somewhat is different from Betza's t[...] construct). The brackets still enclose a sequence of simple Betza moves, which are supposed to be played in that order. But there is no t prefix (which was redundant, because the brackets are never used for any other purpose than chaining the contained moves), and separates the enclosed moves by hyphens (if continuation is mandatory) or question marks (if the move could also end there). This notation is already supported in the Interactive Diagram for simple cases like the Griffon ([F?R]). Supporting it in its full glory is a desire for the future.
The meaning of z in a multi-leg move has also changed; it now means l or r, but the opposit of what the previous leg did. (So that it can be used to specify crooked paths, while q means l or r in the same direction, and can be used to define curved paths.)
I did know about Betza's t[FR] proposal for Griffon, but I had never seen this z(FW) notation. XBetza is only upward compatible with the Betza notation for simple ('single leg') moves, and has its own system for combining these to multi-leg moves, which is more general than any of the suggestions that Betza coined in various scattered places.
The z modifier applied to a slider atom is original Betza notation for a crooked version of the piece, and is still supported in XBetza. On a leaper, such as zW, it never had any meaning.
The role of parentheses has completely changed; in XBeza these indicate zero or more repetitions of the enclosed group. So z(FW) would mean zzFWzFWFWzFWFWFW..., which doesn't really mean anything.
Brackets originally were not used in XBetza, but legs of a move were 'chained' by using an a as separator between the modifiers of each leg. This does the job of unambiguously defining very complex moves, but often leads to a very obfuscated description unsuitable for human digestion. A much clearer notation is possible by using brackets (but in a way that somewhat is different from Betza's t[...] construct). The brackets still enclose a sequence of simple Betza moves, which are supposed to be played in that order. But there is no t prefix (which was redundant, because the brackets are never used for any other purpose than chaining the contained moves), and separates the enclosed moves by hyphens (if continuation is mandatory) or question marks (if the move could also end there). This notation is already supported in the Interactive Diagram for simple cases like the Griffon ([F?R]). Supporting it in its full glory is a desire for the future.
The meaning of z in a multi-leg move has also changed; it now means l or r, but the opposit of what the previous leg did. (So that it can be used to specify crooked paths, while q means l or r in the same direction, and can be used to define curved paths.)