Basic Operability: Does it work?
1.    Might say who cares whether it works. Response is we’re worried about fraud, that you’ll use the fact you have a patent on this non-working invention to deceive others.
2.    Sometimes inoperable because of a mistake and it really is operable, just misdocumented.
3.    Don’t want world where inventor has to bring invention to PTO and show it works. So PTO generally presume it works, put burden on PTO to show it doesn’t work before req inventor to prove that it works.
4.    Operability is not objection to practical econ significance –doesn’t matter if it isn’t efficient, leave that to market.