H. G. Muller wrote on Sun, Jun 28, 2020 12:50 PM UTC:
Sissa is a compound of rook and bishop but its move is not disjunctive, it is conjunctive.
Conjunctive = A and B
Disjunctive = A or B
Am I right?
I have never seen the word 'compound' used in sequential meaning; I would say the Sissa is an (isosceles) hook mover. And I would not say the Tai Shogi Hook Mover is a (conjunctive) compound of two Rooks. The word 'or' usually implies 'and', and if you consider this operations on the move sets, the 'conjunctive compound' of R and B would have no moves (as B and R have no moves in common), and the conjunctive compound of K and R would be the Wazir, etc. There doesn't seem a case where this cumbersome way of describing more elementary move sets is useful, as they tend to all have simple names of their own. Note that the Sissa can neither move as a Rook, nor as a Bishop.
It seems to me the addition of 'disjunctive' serves no other purpose here then sow confusion in a case that otherwise would be correctly understood with 100% certainty.
I have never seen the word 'compound' used in sequential meaning; I would say the Sissa is an (isosceles) hook mover. And I would not say the Tai Shogi Hook Mover is a (conjunctive) compound of two Rooks. The word 'or' usually implies 'and', and if you consider this operations on the move sets, the 'conjunctive compound' of R and B would have no moves (as B and R have no moves in common), and the conjunctive compound of K and R would be the Wazir, etc. There doesn't seem a case where this cumbersome way of describing more elementary move sets is useful, as they tend to all have simple names of their own. Note that the Sissa can neither move as a Rook, nor as a Bishop.
It seems to me the addition of 'disjunctive' serves no other purpose here then sow confusion in a case that otherwise would be correctly understood with 100% certainty.