the conclusion is valid (Camestres).
In Fig. III. AEE—
All M is in P
No M is in S
No S is in P—
the conclusion is invalid, there being illicit process of the Major.
In Fig. IV. AEE is valid (Camenes).
Take EIO. A little reflection shows that this combination is valid in all the Figures if in any, the distribution of the terms in both cases not being affected by their order in predication. Both E and I are simply convertible. That the combination is valid is quickly seen if we remember that in negative moods both Major and Middle must be distributed, and that this is done by E.
EIE is invalid, because you cannot have a universal conclusion with one premiss particular.