For each of the following arguments,
a. Translate the argument into standard form.
b. Name the mood and figure of its standard-form translation.
c. Test its validity using a Venn diagram. If it is valid, give its traditional name.
d. If it is invalid, name the fallacy it commits.

We . . . define a metaphysical sentence as a sentence which purports to express a genuine proposition, but does, in fact, express neither a tautology nor an empirical hypothesis. And as tautologies and empirical hypotheses form the entire class of significant propositions, we are justified in concluding that all metaphysical assertions are nonsensical.
—Alfred J. Ayer, Language, Truth, and Logic , 1936