Hamdy A. Taha, Guy L. Curry, Classical Derivation of the Necessary and Sufficient Conditions for Optimal Linear Programs, Operations Research, Vol. 19, No. 4 (Jul. - Aug., 1971), pp. 1045-1050 Free ...

Rainfall may be a necessary condition for a flood, but it is neither a sufficient condition nor a causal factor to perfectly forecast a flood. If rain comes after weeks of dry weather, soil can ...

Let me now move on to the necessary but not sufficient condition thing: When a company has a good strategy – even a great strategy – it can still fail. Yes, fail.

At this point, while the procedural changes are intended to create the necessary conditions for more housing production, it’s not clear they are even going to accomplish that.