Here is an attempt at defining the three main concepts of Noose (the game I referenced above) in a hopefully useful way (a board with hex cells is assumed):
• A chain of adjacent pieces make up an arc if it is possible to order them from first to last in a sequence where a walk from the first to the last member of the chain, visiting all members in order, will (i) at no point require a turn of more than 60 degrees, and (ii) either require no clockwise turns or no counter-clockwise turns.
• An arc is flanked by a player P if (i) it consists of pieces belonging to only one player, and (ii) player P has two stones adjacent to it in such a way that the original arc plus those two stones still make an arc. (Edit: I'm not 100% sure this is sufficient. There are so many different arcs, maybe I'm failing to imagine some situations. The important, possibly missing, point is that the two stones are the first and the last members of the combined arc.)
• An arc is flippable by a player if that player is the only one flanking it.
So my question is: Is it possible to define the concepts of an arc, of flanking an arc and of a flippable arc in Ludii?
• A chain of adjacent pieces make up an arc if it is possible to order them from first to last in a sequence where a walk from the first to the last member of the chain, visiting all members in order, will (i) at no point require a turn of more than 60 degrees, and (ii) either require no clockwise turns or no counter-clockwise turns.
• An arc is flanked by a player P if (i) it consists of pieces belonging to only one player, and (ii) player P has two stones adjacent to it in such a way that the original arc plus those two stones still make an arc. (Edit: I'm not 100% sure this is sufficient. There are so many different arcs, maybe I'm failing to imagine some situations. The important, possibly missing, point is that the two stones are the first and the last members of the combined arc.)
• An arc is flippable by a player if that player is the only one flanking it.
So my question is: Is it possible to define the concepts of an arc, of flanking an arc and of a flippable arc in Ludii?