The classic one is:
All men are mortal.
Socrates is a man.
Therefor Socrates is mortal.
i.e. If all [tex]A[/tex] are [tex]B[/tex] and all [tex]C[/tex] are [tex]A[/tex] then all [tex]C[/tex] are [tex]B[/tex].
[tex]\overline{\exists x: Ax \land \overline{Bx}} \land \overline{\exists x: Cx \land \overline{Ax}} \Rightarrow \overline{\exists x: Cx \land \overline{Bx}}[/tex]
