I say read again, harder this time. ! ( defined $ENV{EDITOR} && defined $ENV{VISUAL} ) will be false iff both are defined; the suggested solution will only be true iff both are not defined (i.e. neither the one nor the other are defined, which is just what it said to begin with).

In reply to Re^2: interpretation of "neither...nor" by Fletch
in thread Re: interpretation of "neither...nor" by cgmd

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