<p>The ''surjunction'' <math>\overset{J}{\underset{j}{\operatorname{Surj}}}\ q_j</math> of a set of propositions, <math>\{ q_j : j \in J \},</math> is a proposition that is true if and only if exactly one of the <math>q_j\!</math> is untrue.</p> | <p>The ''surjunction'' <math>\overset{J}{\underset{j}{\operatorname{Surj}}}\ q_j</math> of a set of propositions, <math>\{ q_j : j \in J \},</math> is a proposition that is true if and only if exactly one of the <math>q_j\!</math> is untrue.</p> |