merge( a, b, na, nb )
	RecordArray a, b;
	int na, nb;

	{ /*** Merge array b (0...nb-1) into array a (0...na-1) ***/
	while ( nb > 0 )
		if ( na<=0 || a[na-1].k < b[nb-1].k )
				{ nb--; a[na+nb] = b[nb]; }
			else	{ na--; a[na+nb] = a[na]; }
	};