In the customary fashion, the name <math>{}^{\backprime\backprime} x_i {}^{\prime\prime}\!</math> of the variable <math>x_i\!</math> is flexibly interpreted to serve two additional roles. In algebraic and geometric contexts <math>{}^{\backprime\backprime} x_i {}^{\prime\prime}\!</math> is taken to name the <math>i^\text{th}\!</math> ''coordinate function'' <math>\underline{\underline{x_i}} : \mathbb{B}^n \to \mathbb{B}.\!</math> In logical contexts <math>{}^{\backprime\backprime} x_i {}^{\prime\prime}\!</math> serves to name the <math>i^\text{th}\!</math> ''basic property'' or ''simple proposition'', also called <math>{}^{\backprime\backprime} \underline{\underline{x_i}} {}^{\prime\prime},\!</math> that goes into the construction of a propositional universe of discourse, in effect, becoming one of the ''sentence letters'' of a truth table and being used to label one of the ''simple enclosures'' of a venn diagram. | In the customary fashion, the name <math>{}^{\backprime\backprime} x_i {}^{\prime\prime}\!</math> of the variable <math>x_i\!</math> is flexibly interpreted to serve two additional roles. In algebraic and geometric contexts <math>{}^{\backprime\backprime} x_i {}^{\prime\prime}\!</math> is taken to name the <math>i^\text{th}\!</math> ''coordinate function'' <math>\underline{\underline{x_i}} : \mathbb{B}^n \to \mathbb{B}.\!</math> In logical contexts <math>{}^{\backprime\backprime} x_i {}^{\prime\prime}\!</math> serves to name the <math>i^\text{th}\!</math> ''basic property'' or ''simple proposition'', also called <math>{}^{\backprime\backprime} \underline{\underline{x_i}} {}^{\prime\prime},\!</math> that goes into the construction of a propositional universe of discourse, in effect, becoming one of the ''sentence letters'' of a truth table and being used to label one of the ''simple enclosures'' of a venn diagram. |