Which of the following propositions is obverse and logically equivalent to the proposition No umpires are partisans?

Correct option is D

The obversion of a categorical proposition involves two steps:
1. Change the quality of the proposition (affirmative to negative, or negative to affirmative).
2. Replace the predicate with its complement.
The given proposition is:
· "No umpires are partisans"
This is a universal negative (E) proposition. The obverse of an E proposition is a universal affirmative (A) proposition with the predicate replaced by its complement.
1. Change the quality from negative ("No") to affirmative ("All").
2. Replace the predicate partisans with its complement non-partisans.
Thus, the obverse becomes:
· "All umpires are non-partisans"
This corresponds to option (d).
Information Booster: 1. Obversion: A logical operation that involves changing the quality of the proposition and replacing the predicate with its complement.
2. E Proposition: A universal negative statement ("No S are P").
3. A Proposition: A universal affirmative statement ("All S are P").
4. Complement: The set of all things not included in a given category.