Q: Consider the following two propositions: Oswald shot Kennedy; Oswald did not shoot Kennedy. Suppose that we have two pieces of reasoning, one with the first as conclusion and the other with the second as conclusion, and each with a single premise that is true. Explain why the pieces of reasoning cannot both be valid.
A: They both cannot be valid as they are contradictions
如果P = True - 結論=真：。拍攝K.
如果P = True - 結論=真：。 O沒拍K