How to test a tree

We address the problem of verifying that a tree is connected using probe operations which check mutual connectivity between two (or more) leaves of the tree. We present optimal algorithms for determining minimal probe sets that detect all possible edge and vertex faults in arbitrary trees. Our results are of particular interest for the testing of interconnection substrates in VLSI multichip module packaging technologies. q 1998 John Wiley & Sons, Inc. Networks 32: 189–197, 1998