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| their informal comprehension can be converted into an explicit subject matter, | | their informal comprehension can be converted into an explicit subject matter, |
| one that depends on grasping an array of increasingly formalized concepts. | | one that depends on grasping an array of increasingly formalized concepts. |
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− | IDS. Note 121
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− | 1.3.10.3. Propositions and Sentences (cont.)
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| | NB. In the following asciification of a pre-existing text, | | | NB. In the following asciification of a pre-existing text, |
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| of distinction, respectively, between the boolean values of the | | of distinction, respectively, between the boolean values of the |
| entities in question. | | entities in question. |
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− | IDS. Note 122
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− | 1.3.10.3. Propositions and Sentences (cont.)
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| In logical studies, one tends to be interested in all of the | | In logical studies, one tends to be interested in all of the |
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| the values of its putative arguments, is not as variable in its values as | | the values of its putative arguments, is not as variable in its values as |
| the values of its variables are allowed to be. | | the values of its variables are allowed to be. |
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− | IDS. Note 123
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− | o~~~~~~~~~o~~~~~~~~~o~~~~~~~~~o~~~~~~~~~o~~~~~~~~~o
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− | 1.3.10.3. Propositions and Sentences (cont.)
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| The "indicator function" or the "characteristic function" of a set Q c X, | | The "indicator function" or the "characteristic function" of a set Q c X, |
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| subset of its designated universe, and even though one will eventually, | | subset of its designated universe, and even though one will eventually, |
| most likely, want to know exactly what subset that is. | | most likely, want to know exactly what subset that is. |
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− | IDS. Note 124
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− | 1.3.10.3. Propositions and Sentences (cont.)
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| According to the stated understandings, a proposition is a function that | | According to the stated understandings, a proposition is a function that |
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| [| f |] = f^(-1)(%1%) = {x in X : f(x) = %1%}. | | [| f |] = f^(-1)(%1%) = {x in X : f(x) = %1%}. |
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− | IDS. Note 125
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− | o~~~~~~~~~o~~~~~~~~~o~~~~~~~~~o~~~~~~~~~o~~~~~~~~~o
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− | 1.3.10.3. Propositions and Sentences (cont.)
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| The definition of a fiber, in either the general or the boolean case, | | The definition of a fiber, in either the general or the boolean case, |
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| that is identified by the sign "f(x)", and thus an object that might | | that is identified by the sign "f(x)", and thus an object that might |
| as well be identified with the value f(x). | | as well be identified with the value f(x). |
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− | IDS. Note 126
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− | o~~~~~~~~~o~~~~~~~~~o~~~~~~~~~o~~~~~~~~~o~~~~~~~~~o
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− | 1.3.10.3. Propositions and Sentences (cont.)
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| The upshot of this whole discussion of evaluation is that it allows one to | | The upshot of this whole discussion of evaluation is that it allows one to |
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| idea of an "assertion" and notion of an "equation", and it allows one | | idea of an "assertion" and notion of an "equation", and it allows one |
| to treat logical equality on a par with the other logical operations. | | to treat logical equality on a par with the other logical operations. |
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− | IDS. Note 127
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− | o~~~~~~~~~o~~~~~~~~~o~~~~~~~~~o~~~~~~~~~o~~~~~~~~~o
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− | 1.3.10.3. Propositions and Sentences (cont.)
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| | | |
| As a purely informal aid to interpretation, I frequently use the letters | | As a purely informal aid to interpretation, I frequently use the letters |
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| since the apodosis is intended to do nothing more than to abbreviate and | | since the apodosis is intended to do nothing more than to abbreviate and |
| to summarize what is already stated in the protasis. | | to summarize what is already stated in the protasis. |
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− | IDS. Note 128
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− | o~~~~~~~~~o~~~~~~~~~o~~~~~~~~~o~~~~~~~~~o~~~~~~~~~o
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− | 1.3.10.3. Propositions and Sentences (cont.)
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| | | |
| A "boolean connection" of degree k, also known as a "boolean function" | | A "boolean connection" of degree k, also known as a "boolean function" |
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| any sign that is taken to denote an indicator function, or any sign whose | | any sign that is taken to denote an indicator function, or any sign whose |
| object happens to be a function of the form f : X -> %B%. | | object happens to be a function of the form f : X -> %B%. |
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− | IDS. Note 129
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− | 1.3.10.3. Propositions and Sentences (concl.)
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| An "expression" is a type of sign, for instance, a term or a sentence, | | An "expression" is a type of sign, for instance, a term or a sentence, |
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| Indeed, there are problems involved in this whole style of definition | | Indeed, there are problems involved in this whole style of definition |
| that need to be discussed, and doing this requires a slight excursion. | | that need to be discussed, and doing this requires a slight excursion. |
| + | </pre> |
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− | o~~~~~~~~~o~~~~~~~~~o~~~~~~~~~o~~~~~~~~~o~~~~~~~~~o
| + | =====1.3.10.4. Empirical Types and Rational Types===== |
− | | |
− | IDS. Note 130
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− | o~~~~~~~~~o~~~~~~~~~o~~~~~~~~~o~~~~~~~~~o~~~~~~~~~o
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− | 1.3.10.4. Empirical Types and Rational Types | |
| | | |
| + | <pre> |
| In this Subsection, I want to examine the style of definition that I used | | In this Subsection, I want to examine the style of definition that I used |
| to define a sentence as a type of sign, to adapt its application to other | | to define a sentence as a type of sign, to adapt its application to other |