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List:       spamassassin-users
Subject:    Re: OR NOT Logic
From:       mouss <usebsd () free ! fr>
Date:       2006-05-03 22:14:57
Message-ID: 44592B61.8030902 () free ! fr
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Dan wrote:
>
> Is:
>
> A && (B || C || D || E || F)
>
> equivalent to?:
>
> A && (!B && !C && !D && !E && !F)
>
No.  The DeMorgan laws are:
    ! ( A && B)    =  !A  || !B
    !(A || B)         == !A && !B
so you _dispatch_ the '!' and replace || with && and conversely.

example:

    if it is _not_ spam _and_ it is not virus, deliver it; else 
quarantine it
is the same as
    if it is _either_ spam _or_ virus, quarantine it. else deliver it



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