− | The '''minimal negation operator''' <math>\nu~\!</math> is a [[multigrade operator]] <math>(\nu_k)_{k \in \mathbb{N}}~\!</math> where each <math>\nu_k~\!</math> is a <math>k~\!</math>-ary [[boolean function]] defined in such a way that <math>\nu_k (x_1, \ldots , x_k) = 1~\!</math> in just those cases where exactly one of the arguments <math>x_j~\!</math> is <math>0.~\!</math> | + | The '''minimal negation operator''' <math>\nu~\!</math> is a [[multigrade operator]] <math>(\nu_k)_{k \in \mathbb{N}}~\!</math> where each <math>\nu_k~\!</math> is a <math>k~\!</math>-ary [[boolean function]] defined by the rule that <math>\nu_k (x_1, \ldots , x_k) = 1~\!</math> if and only if exactly one of the arguments <math>x_j~\!</math> is <math>0.~\!</math> |
− | In contexts where the initial letter <math>\nu~\!</math> is understood, the minimal negation operators can be indicated by argument lists in parentheses. In the following text a distinctive typeface will be used for logical expressions based on minimal negation operators, for example, <math>\texttt{(x, y, z)}~\!</math> = <math>\nu (x, y, z).~\!</math> | + | In contexts where the initial letter <math>\nu~\!</math> is understood, the minimal negation operators can be indicated by argument lists in parentheses. In the following text a distinctive typeface will be used for logical expressions based on minimal negation operators, for example, <math>\texttt{(x, y, z)} = \nu (x, y, z).~\!</math> |
− | The first four members of this family of operators are shown below, with paraphrases in a couple of other notations, where tildes and primes, respectively, indicate logical negation. | + | The first four members of this family of operators are shown below. The third and fourth columns give paraphrases in two other notations, where tildes and primes, respectively, indicate logical negation. |