I especially liked the discussion under Example 1 about reformulating "negative" sentences into "positive" sentences. The briefest amount of work in mathematic

I especially liked the discussion under Example 1 about reformulating "negative" sentences into "positive" sentences. The briefest amount of work in mathematical deduction or symbolic logic will cause you to raise an eyebrow whenever anyone insists "you can't prove a negative." Every negative statement has a positive formulation buried within it. Or, no negative statement exists that lacks a positive formulation, and vice versa.