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Hi, I have a problem with this example. Please check whether the expression is a tautology. [Math] [(p \ wedge q) \ rightarrow r] \ rightarrow [(p \ rightarrow y) \ wedge (q \ rightarrow r)] siron12 just starting Posts: 6 Joined: 07 Oct 2012, 16:01 Gender: Received Thanks: 0
This is not a tautology. Just consider [math] p = 0 \, \, q = 1 \, \, \, r = 0 \\ then \\ p \ wedge q = 0 \\ t = [(p \ wedge q) \ rightarrow y} = 1 \\ z = [(p \ rightarrow y) \ wedge (q \ rightarrow r)] = 0 \\ [t \ rightarrow z] = 0 analogy comes 0 when [math] p = 1 \, \ q = 0, \, \, r = 0, and \, \; \\ when p = 1, q = 1, r = 0.
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