In Cambridge's experience, the phrase 'purely hypothetical' never actually means purely hypothetical. Especially in the realm of equations.

He drops the PADD back onto the table.

"Often, one wouldn't know," he says. "Other times, it would be patently obvious. And other times still, the judgment would be based on intake and processing of data below the conscious level. With the number of variables, how would you know becomes a pointless and farcical question, impossible to answer in the abstract."