PT 58, S4, Q15; Proofs relying crucially on computers...

[cyruswhittaker]

Can you please explain this question? I'm having trouble between choices B and C.

[bbirdwell]

Here's what we know:

1. Proofs w/o computers = more certainty than computer proofs

2. humans alone cannot verify computer proofs

3. sometimes a calculator helps humans, but this kind of computer is a convenience rather than a supplement to cognition

As usual, what helps the most is boiling the choice down to its essential elements. Don't let the double negatives confuse you! In (B), at the end, it doesn't matter if humans can detect the errors or not -- the first sentence of the stimulus says there is uncertainty in computer proofs. That's all we need know in order to choose this choice.

(B) "We can never be sure..." = "There is uncertainty that computer proofs are free of errors." This is true!

(C) Every time a computer replaces a human, the certainty is reduced. Hmm. Every time? What about when that computer is a calculator, which were let off the hook in the final sentence? Also, does "replacement" of a human make the proof "crucially reliant" on computers? Maybe so, maybe no. This choice is not provable.