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| + | |
| + | =Work In Progress= |
| + | |
| + | ==4. Expository Examples== |
| + | |
| + | '''(Work In Progress)''' |
| + | |
| + | Consider the logical proposition represented by the following venn diagram: |
| + | |
| + | <center><pre> |
| + | o-----------------------------------------------------------o |
| + | | X . . . . . . . . . . . . . . . . . . . . . . . . . . . . | |
| + | | . . . . . . . . . . . . . . . . . . . . . . . . . . . . . | |
| + | | . . . . . . . . . . .o-------------o. . . . . . . . . . . | |
| + | | . . . . . . . . . . / . . . . . . . \ . . . . . . . . . . | |
| + | | . . . . . . . . . ./. . . . . . . . .\. . . . . . . . . . | |
| + | | . . . . . . . . . / . . . . . . . . . \ . . . . . . . . . | |
| + | | . . . . . . . . ./. . . . . . . . . . .\. . . . . . . . . | |
| + | | . . . . . . . . / . . . . . . . . . . . \ . . . . . . . . | |
| + | | . . . . . . . .o. . . . . . . . . . . . .o. . . . . . . . | |
| + | | . . . . . . . .|. . . . . . U . . . . . .|. . . . . . . . | |
| + | | . . . . . . . .|. . . . . . . . . . . . .|. . . . . . . . | |
| + | | . . . . . . . .|. . . . . . . . . . . . .|. . . . . . . . | |
| + | | . . . . . . . .|. . . . . . . . . . . . .|. . . . . . . . | |
| + | | . . . . . . . .|. . . . . . . . . . . . .|. . . . . . . . | |
| + | | . . . . . . o--o----------o . o----------o--o . . . . . . | |
| + | | . . . . . ./. . \%%%%%%%%%%\./%%%%%%%%%%/ . .\. . . . . . | |
| + | | . . . . . / . . .\%%%%%%%%%%o%%%%%%%%%%/. . . \ . . . . . | |
| + | | . . . . ./. . . . \%%%%%%%%/%\%%%%%%%%/ . . . .\. . . . . | |
| + | | . . . . / . . . . .\%%%%%%/%%%\%%%%%%/. . . . . \ . . . . | |
| + | | . . . ./. . . . . . \%%%%/%%%%%\%%%%/ . . . . . .\. . . . | |
| + | | . . . o . . . . . . .o--o-------o--o. . . . . . . o . . . | |
| + | | . . . | . . . . . . . . |%%%%%%%| . . . . . . . . | . . . | |
| + | | . . . | . . . . . . . . |%%%%%%%| . . . . . . . . | . . . | |
| + | | . . . | . . . . . . . . |%%%%%%%| . . . . . . . . | . . . | |
| + | | . . . | . . . .V. . . . |%%%%%%%| . . . .W. . . . | . . . | |
| + | | . . . | . . . . . . . . |%%%%%%%| . . . . . . . . | . . . | |
| + | | . . . o . . . . . . . . o%%%%%%%o . . . . . . . . o . . . | |
| + | | . . . .\. . . . . . . . .\%%%%%/. . . . . . . . ./. . . . | |
| + | | . . . . \ . . . . . . . . \%%%/ . . . . . . . . / . . . . | |
| + | | . . . . .\. . . . . . . . .\%/. . . . . . . . ./. . . . . | |
| + | | . . . . . \ . . . . . . . . o . . . . . . . . / . . . . . | |
| + | | . . . . . .\. . . . . . . ./.\. . . . . . . ./. . . . . . | |
| + | | . . . . . . o-------------o . o-------------o . . . . . . | |
| + | | . . . . . . . . . . . . . . . . . . . . . . . . . . . . . | |
| + | | . . . . . . . . . . . . . . . . . . . . . . . . . . . . . | |
| + | o-----------------------------------------------------------o |
| + | </pre> |
| + | '''Figure 1. Proposition''' <math>q : X \to \mathbb{B}</math> |
| + | </center> |
| + | |
| + | The following language is useful in describing the facts represented by the venn diagram. |
| + | |
| + | * The universe of discourse is a set, <math>X,\!</math> represented by the area inside the large rectangle. |
| + | |
| + | * The boolean domain is a set of two elements, <math>\mathbb{B} = \{ 0, 1 \},</math> represented by the two distinct shadings of the regions inside the rectangle. |
| + | |
| + | * According to the conventions observed in this context, the algebraic value 0 is interpreted as the logical value <math>\operatorname{false}</math> and represented by the lighter shading, while the algebraic value 1 is interpreted as the logical value <math>\operatorname{true}</math> and represented by the darker shading. |
| + | |
| + | * The universe of discourse <math>X\!</math> is the domain of three functions <math>u, v, w : X \to \mathbb{B}</math> called ''basic'', ''coordinate'', or ''simple'' propositions. |
| + | |
| + | * As with any proposition, <math>p : X \to \mathbb{B},</math> a simple proposition partitions <math>X\!</math> into two fibers, the fiber of 0 under <math>p,\!</math> defined as <math>p^{-1}(0) \subseteq X,</math> and the fiber of 1 under <math>p,\!</math> defined as <math>p^{-1}(1) \subseteq X.</math> |
| + | |
| + | * Each coordinate proposition is represented by a "circle", or a simple closed curve, that divides the rectangular region into the region exterior to the circle, representing the fiber of 0 under <math>p,\!</math> and the region interior to the circle, representing the fiber of 1 under <math>p.\!</math> |
| + | |
| + | * The fibers of 1 under the propositions <math>u, v, w\!</math> are the respective subsets <math>U, V, W \subseteq X.</math> |
| + | |
| + | '''…''' |
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| =Material To Be Collated= | | =Material To Be Collated= |