$\"\"$

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Property $\"\"$ : $\"\"$ .

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Proof :

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Assume that $\"\"$ and $\"\"$ .

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Consider $\"\"$ .

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Find the value of $\"\"$ .

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$\"\"$

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Find the value of $\"\"$ .

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$\"\"$ \ \

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$\"\"$ .

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Substiute the values of $\"\"$ and $\"\"$ in the property.

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$\"\"$

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$\"\"$

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Consider $\"\"$ .

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$\"\"$

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$\"\"$

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Therefore the property ontained is equal to $\"\"$ .

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Therefore $\"\"$ .

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$\"\"$

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$\"\"$