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I wish to formulate a proof that if $x+y = x+z$ and $xy$ = $xz$ then $y=z$. I'm just beginning my study of Boolean algebra, but is $y=z$ not self evident from the stated equations?

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    What happens if you add $x$ to both sides of the first equality ?2012-12-06
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    $x+x=x$ so both sides remain the same?2012-12-06
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    Does '$+$' stands for 'xor' or for 'or' in your definition?2012-12-06
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    Oh sorry, '+' stands for 'or'2012-12-06
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    Ok, my mistake then. From $x+y=x+z$ you can derive $(\neg x)y = (\neg x)z$ and then compute $(\neg x + x)y = \dots$.2012-12-06
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    Thank you, I will try this.2012-12-06

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