An ordered pair 
of nonnegative integers such that there is some set of 
points and 
edges whose removal disconnects the graph and there is no
set of 
nodes and 
edges or 
nodes and 
edges with this property.
Connectivity Pair
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References
Harary, F. Graph Theory. Reading, MA: Addison-Wesley, 1994.Referenced on Wolfram|Alpha
Connectivity PairCite this as:
Weisstein, Eric W. "Connectivity Pair." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/ConnectivityPair.html