gkoberger said:
∃m∈M ¬S(m)
then mmlgr said pardon me, but:
∃m∈M S(m)
and then you were like:
∃m∈M S(m)≡¬∃m∈M ¬S(m)
but I've got to tell you:
∃m∈M S(m)≡¬∀m∈M ¬S(m)
∃m∈M ¬S(m)≡¬∀m∈M S(m)
∃m∈M S(m)≢∀m∈M S(m)