💡📝H. G. Muller wrote on Sun, Oct 22, 2023 08:09 AM UTC:
As I understand it this is all about how pieces with distant moves could be 'non-jumping', and specifying in detail which squares have to be empty for the move to be allowed. As the number of possibilities for this grows combinatorially with the length of the leap (there are 2 to the power N patterns of occupied vs empty squares if there are N squares between origin and destination, and for each of those it could be independently chosen whether the move is allowed or not, for a total of 2^(2^N) possibilities), this can obviously not be indicated with different modifier prefixes. The original Betza notation supported only a few cases, through the n and j modifiers (i.e. only if all empty, or only if exactly one occupied, while the default is 'irrespective of any occupants').
In XBetza it is already possible to specify each pattern, by defining the move as a multi-leg move consisting of K steps specifying the trajectory, and give each of the non-final steps a p, m or mp mode (for 'must be occupied', 'must be empty' (the default) or 'don't care', respectively). So if we use the H leap as an example (2 intermediate squares), afmpafW would be possible only if the first square was empty, mpafafW only if the second square was empty, afafW would require both to be empty (for which the shorthand nH exists), pafafW would require the first to be occupied, the second to be empty, etc. To get OR-like behavior you can simply specify all allowed possibilities; afmpafWmpafafW would mean either the first or second square (or both) should be empty, while afpafWpafafW would mean one square must be empty, the other occupied (shorthand jH).
As I understand it this is all about how pieces with distant moves could be 'non-jumping', and specifying in detail which squares have to be empty for the move to be allowed. As the number of possibilities for this grows combinatorially with the length of the leap (there are 2 to the power N patterns of occupied vs empty squares if there are N squares between origin and destination, and for each of those it could be independently chosen whether the move is allowed or not, for a total of 2^(2^N) possibilities), this can obviously not be indicated with different modifier prefixes. The original Betza notation supported only a few cases, through the n and j modifiers (i.e. only if all empty, or only if exactly one occupied, while the default is 'irrespective of any occupants').
In XBetza it is already possible to specify each pattern, by defining the move as a multi-leg move consisting of K steps specifying the trajectory, and give each of the non-final steps a p, m or mp mode (for 'must be occupied', 'must be empty' (the default) or 'don't care', respectively). So if we use the H leap as an example (2 intermediate squares), afmpafW would be possible only if the first square was empty, mpafafW only if the second square was empty, afafW would require both to be empty (for which the shorthand nH exists), pafafW would require the first to be occupied, the second to be empty, etc. To get OR-like behavior you can simply specify all allowed possibilities; afmpafWmpafafW would mean either the first or second square (or both) should be empty, while afpafWpafafW would mean one square must be empty, the other occupied (shorthand jH).