(1) All solid substances are material.
(2) All the men who do not row play cricket.
(3) All impeccable beings are other than human,
(4) Some prejudiced persons are not dishonest.
3. Prove indirectly the truth of the contrapositive of 'All A is B.'
4. Criticise the following as immediate inferences—
(1) All wise men are modest.
.'. No immodest men are wise.
(2) Some German students are not industrious.
.'. Some industrious students are not Germans.
(3) Absolute difference excludes all likeness.
.'. Any likeness is a proof of sameness.
(4) None but the brave deserve the fair.
.'. All brave men deserve the fair.