******** fig6.29 **********

	PRIORITY_QUEUE
	insert1( element_type x, PRIORITY_QUEUE H )
	{
		tree_ptr single_node;

/*1*/		single_node = (tree_ptr) malloc( sizeof ( struct tree_node ) );
/*2*/		if( single_node == NULL )
/*3*/			fatal_error("Out of space!!!");
		else
		{
/*4*/			single_node->element = x; single_node->npl = 0;
/*5*/			single_node->left = single_node->right = NULL;
/*6*/			H = merge( single_node, H );
		}
/*7*/		return H;
	}