Question 971804
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"A dolphin cannot fly and a bird can swim" is false.
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Let variables P and Q stand for the 'positive' idea of verbs: 
(That is, we use 'can fly' rather than 'cannot fly'):

Let P = "A dolphin can fly."  
Let Q = "A bird can swim. 

Then only the first part in quotation marks, that is, 

"A dolphin cannot fly and a bird can swim"

(without "is false") in symbols is

~P & Q

Then annexing of "is false" means that we are negating that and we must put
parentheses around it and a ~ (negation symbol) before it.
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~(~P & Q)
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Demorgan's law says this is equivalent to
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~~P v ~Q
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The double negation before P makes it
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P v ~Q

A dolphin can fly or a bird cannot swim.
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That is one possible solution.  

However there is another equivalent statement we could get.

By commutation we get:
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~Q v P
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which in words is:
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"A bird cannot swim or a dolphin can fly
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Then we can use 'material implication' to get
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Q -> P
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which means
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If Q then P 
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which in words is
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If a bird can swim, then a dolphin can fly.
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That is another possible solution.

[All statements above which are in red are equivalent to the given statement.]

Edwin</pre>