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    <p>This sort of problem, given a truth table, minimize the logic required to reproduce the truth values, is often nicely treated, with <a href="http://en.wikipedia.org/wiki/Karnaugh_map" rel="nofollow">Karnaugh Maps</a></p> <p>Your truth table here looks like:</p> <pre> v1 v2 f(v1, v2) t t t t f f f t f f f t </pre> <p>And actually, as others have noted, given that truth table, a basic familiarity with logic should right away yield the function !<a href="http://en.wikipedia.org/wiki/Exclusive_or" rel="nofollow">xor</a></p> <p>However, if you take the truth table and draw it as a Karnaugh Map, it looks like:</p> <pre> v2 f t --------- v f| t | f | 1 t| f | t | --------- </pre> <p>And the function looks like: !v1!v2 || v1v2 which if you look at <a href="http://en.wikipedia.org/wiki/Karnaugh_map#2-variable_map_examples" rel="nofollow">2 variable karnaugh map examples</a> again can be seen to simplify to ! <a href="http://en.wikipedia.org/wiki/Exclusive_or" rel="nofollow">xor</a></p> <p>Admittedly, 2 variable karnaugh maps are probably best treated with the ordinary logical operations by well, familiarity and memorization. But when expanding beyond 2 variables, Karnaugh maps are very illuminating -- you should look into them.</p> <ul> <li><a href="http://www.facstaff.bucknell.edu/mastascu/elessonshtml/Logic/Logic3.html" rel="nofollow">http://www.facstaff.bucknell.edu/mastascu/elessonshtml/Logic/Logic3.html</a></li> <li><a href="http://www.allaboutcircuits.com/vol_4/chpt_8/5.html" rel="nofollow">http://www.allaboutcircuits.com/vol_4/chpt_8/5.html</a></li> <li><a href="http://k-map.sourceforge.net/" rel="nofollow">http://k-map.sourceforge.net/</a></li> </ul>
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    1. POBetter ways to find if both variables are true or both are false
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    1. USJerry Asher
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    1. COInteresting choice of upvoted solutions, I tend to think that result = !(v1 xor v2) is more clear than result = (v1 == v2).
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      1. USJerry Asher
    2. COI politely suggest that you get some more coffee … if you find `!(a ^ b)` to be clearer than `a == b` then you must still be asleep. And having a nightmare.
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      1. USKonrad Rudolph
 

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