******** fig4.57 **********

	void
	zig_left( splay_ptr x )
	{
		splay_ptr p, B;

		p = x->parent;
		B = x->right;

		x->right = p;		/* x's new right child is p*/
		x->parent = NULL;	/* x will now be a root */

		if( B != NULL )
			B->parent = p;
		p->left = B;
		p->parent = x;
	}