Everybody loves somebody
--------
記号
∀：all
∃：some
￢: not
--------
Everybody loves somebody
⇔(∀x)[x loves ∃y]
⇔(∀x)(∃y)[x loves y]
その否定
⇔Someone loves nobody
⇔(∃x)[x does not love ∀y]
⇔(∃x)(∀y)[x does not love y]
⇔(∃x)(∀y)￢[x loves y]
つまり否定の対応関係は；
∀ →∃
∃ →∀
[] →￢[]