木構造の定義 # type 'a tree = Lf | Br of 'a * 'a tree * 'a tree;; type 'a tree = Lf | Br of 'a * 'a tree * 'a tree # type 'a rosetree = RLf | RBr of 'a * 'a rosetree list;; type 'a rosetree = RLf | RBr of 'a * 'a rosetree list # let rtree …