a problem to solve

[John Salerno]

John Salerno wrote:
> mensanator at aol.com wrote:
> 
>> No. First of all, combining them with the & operator would be
>> the asnswer to having all four lamps lit in the same position.
>> But you want exactly 3 (in any combination). The correct way
>> to combine the switches (using my answer of a[7] b[2] c[5] d[3])
>> is to use the boolean expression I gave you initially:
> 
> Ah, that makes sense. I think I have a handle on it now. Of course, you 
> did the grunt work of making the hex list, which might not have been so 
> fun, but now I can work on using it to get the solution. Once I do, I'd 
> love to compare my answer to yours, because something tells me yours 
> will be much more elegant. :)

p.s. is there an xor operator in python?