Unlink the root item
void PtTreeRemoveList( PtWidget_t *tree, PtTreeItem_t *first );
This function unlinks the item first and its brothers (together with their children) from their parent (and previous brother) and sets their gen.father fields to NULL:
The tree argument must point to the PtTree widget that contains the items, or can be NULL if the items don't belong to any tree.
Note that if tree is NULL and first has no parent but has a previous brother, then the function won't be able to find the previous brother and therefore can't unlink first from its previous brother.
PtTree, PtTreeAddAfter(), PtTreeAddFirst(), PtTreeAllocItem(), PtTreeFreeAllItems(), PtTreeFreeItems(), PtTreeItem_t, PtTreeRemoveChildren(), PtTreeRemoveItem()