| Inconsistency | The author asserts more than one proposition such that the propositions cannot all be true.
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| In such a case, the propositions may be contradictories or they may be
contraries.
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| Examples: |
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(i) Montreal is about 200 km from Ottawa, while Toronto is
400 km from Ottawa. Toronto is closer to Ottawa than
Montreal.
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(ii) John is taller than Jake, and Jake is taller than Fred,
while Fred is taller than John.
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| Proof: |
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Assume that one of the statements is true, and then use it as
a premise to show that one of the other statements is false.
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