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I read a paper which talks about "a logic formula in which each variable appears at most twice unnegated and once negated". The term "unnegated" is double-negative, which makes it slightly unclear. Is there a more positive term to denote a variable that is not negated?

I looked in an English thesaurus, but all suggestions seem out-of-context in logic.

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    $\begingroup$ "... appears at most twice positively (as a positive literal) and once negatively (as a negative literal)." The parenthetical explanations are optional. $\endgroup$ – Yuval Filmus Jan 29 '14 at 18:53
  • $\begingroup$ @YuvalFilmus Thanks! I used your suggestion in the following Wikipedia page: en.wikipedia.org/wiki/… $\endgroup$ – Erel Segal-Halevi Jan 29 '14 at 19:32
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    $\begingroup$ I wouldn't consider the term "unnegated" to be a double negative, since the "un-" prefix applies to the variable itself while the "-negated" stem applies to the truth or falsity represented by that variable. Other possibilities would be "true form" and either "complemented form" or "negated form". $\endgroup$ – supercat Jan 30 '14 at 17:36
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You can rephrase your statement as "a logic formula in which each variable appears at most twice positively and once negatively". This relies on the common usage of positive and negative literals.

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You often see negative variables ($\neg x$) and positive variables ($x$). A literal is either a positive or a negative variable.

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