[FOM] Benenson

[Robert Black]

Introductory treatments of the notion of nonconstructive proof almost 
always give as an example the proof that there is an irrational x 
such that x raised to the power root 2 is rational (because root 2 to 
the root 2 is either rational or not and ...). This proof is 
attributed to 'Benenson'. Does anyone happen to know who Benenson is 
or was? Googling the name gives the proof and various Benensons (e.g. 
the founder of Amnesty International) but doesn't seem to associate 
the proof with any particular Benenson.

Robert