+struct treenode *new_node(int op, struct treenode *l, struct treenode *r, int exprcount);
+struct treenode *new_number(long val, int exprcount);
+struct treenode *new_param(int op, char *name, struct treenode *l, struct treenode *r, int param_index, int exprcount);
+struct treenode *new_field(char *name, struct treenode *l, struct treenode *r, int soffset, int exprcount);
+void write_tree(struct treenode *node, int ident);