Determine Which of the Lettered Claims Below Is Equivalent to the Following

question 71

Multiple Choice

Determine which of the lettered claims below is equivalent to the following: Although Steve can give blood, he has not been tested. (This is easy to do if you symbolize the claims first and have some familiarity either with truth tables or with the Group II rules for derivations-the truth-functional equivalences.)

• A)If Steve can give blood, then he has been tested.
• B)If Steve has been tested, then he can give blood.
• C)Steve cannot give blood, and he has not been tested.
• D)Steve has not been tested, but he can give blood.

---

Definitions:

Subcontraries

In traditional logic, these are propositions that can both be true but cannot both be false at the same time in Aristotle's square of opposition.

Obverses

In logic, statements that are logically equivalent but expressed in inverse form, typically through negation or contraposition.

Relationship

The process by which two or more ideas, objects, or individuals are related, or the status of having a relationship.

Contradictories

Statements that cannot both be true or both be false at the same time.