Pseudocode from Aho, Hopcroft, and Ullman for deleting in a 2-3 tree

Deletion always begins at a leaf node
   Delete the leaf node, updating parent/root
   Let f be the parent of the node just deleted (or NULL if leaf was root)
   while f is an illegal interior node [not NULL or leaf, with one child]
      if f has no parent
         make the single child of f the new root
         delete f
         Set f to the root [for while loop condition]
      else
         let g be parent of f --- known to have 2 or 3 children
         if one of f's siblings is a 3-node
            move one child from the 3-node into f    [That is, f becomes legal]
            update L and M everywhere
         else
            give f's remaining child to one of f's siblings
            delete f
            update L and M everywhere
            Set f to g [for while loop condition]
   end-while