\"\"

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Let \"\" and \"\".

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Case (i):

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\"\"

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\"\"

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\"\"

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\"\"

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\"\".

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Case (ii):

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\"\"

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\"\"

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\"\"

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\"\"

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\"\".

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if \"\" and \"\" are unit matrix then \"\" is possible,other than impossible. \"\"

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if \"\" and \"\" are unit matrix then \"\" is possible, other than impossible.