#include <stdio.h>
#include "Tree.h"

void prefix(Tree T, void process(TreeElementType))
/* NB. process is a procedure formal-parameter */
 { if( T != NULL )
    { process(T->elt);
      prefix( T->left,  process );
      prefix( T->right, process );
    }
 }/*prefix*/

/* Prefix Tree Traversal. */