struct treenode *new_arg(struct treenode *l, struct treenode *r, int soffset);
struct treenode *new_nothing(void);
void write_tree(struct treenode *node, int ident);
struct treenode *new_arg(struct treenode *l, struct treenode *r, int soffset);
struct treenode *new_nothing(void);
void write_tree(struct treenode *node, int ident);