struct treenode *new_node(int op, struct treenode *l, struct treenode *r);
struct treenode *new_number(long val);
struct treenode *new_param(int op, struct treenode *l, struct treenode *r, int param_index);
struct treenode *new_node(int op, struct treenode *l, struct treenode *r);
struct treenode *new_number(long val);
struct treenode *new_param(int op, struct treenode *l, struct treenode *r, int param_index);