Op wo 06-08-2003, om 10:55 schreef He HongFu: > Hi, All > Sorry, a simple question, where is the "tree"'s definition? I cannot find it in "tree.h" and any other, "tree" is in coretypes.h. It's a pointer to "union tree_node", which is defined in tree.h (as are all its member structs). Gr. STeven