# Question about example prob. given in ALU

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## Question about example prob. given in ALU

 I have a question regarding the worked out example that the book explains on page 35 in chapter 2. In order to determine the inputs for the function x-1, they are using the boolean values of 1 and 0, 1 being true and 0 false. So when the bit is 0, the x input is not zeroed or negated, and the no bit is not negated, and when 1, y is zeroed then negated bitwise, and the arithemitic is addition. I'm I correct?
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## Re: Question about example prob. given in ALU

 You've got the right idea. Isn't it interesting how by combining a handful of operations on x and y we can exhibit different higher-order operations? Search the forum for the "ALU Worksheet" if you need help convincing yourself about how this works.
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## Re: Question about example prob. given in ALU

 This post was updated on . Attached is my ALU worksheet solutions(there was no attachment option when I tried to send this via email).
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## Re: Question about example prob. given in ALU

 Cool. But why are you posting this? Maybe its best not to, in order to prevent others from being tempted to look at solutions rather than work through the worksheet.
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## Re: Question about example prob. given in ALU

 That's why I was gonna try to send it to you via email but I couldn't see an option for attaching a file. I've deleted it from my previous post though.
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## Re: Question about example prob. given in ALU

 I'm still not getting the purpose of writing the decimal values for f(x,y), nor the two four bit binary numbers located at the top of each chart (ex. f(x,y)=x "0100 4", 0100 for x and 0101 for y. )