− | When giving names and habitations to things by the use of letters and types, a certain flexibility may be allowed in the roles assigned by interpretation. For example, in the form "p: U -> B", the name "p" may be taken to denote a proposition or a function, indifferently, and the type U may be associated with a set of interpretations or a set of boolean vectors, correspondingly, whichever makes sense in a given context of use. One dimension that does matter is drawn through these three beads: propositions, interpretations, and values. On the alternate line it is produced by the distinctions among collections, individuals, and values. | + | When giving names and habitations to things by the use of letters and types, a certain flexibility may be allowed in the roles assigned by interpretation. For example, in the form "''p'' : ''U'' → '''B'''", the name "''p''" may be taken to denote a proposition or a function, indifferently, and the type ''U'' may be associated with a set of interpretations or a set of boolean vectors, correspondingly, whichever makes sense in a given context of use. One dimension that does matter is drawn through these three beads: propositions, interpretations, and values. On the alternate line it is produced by the distinctions among collections, individuals, and values. |
| One relation that is of telling importance is the relation of interpretations to the value they give a proposition. In its full sense and general case this should be recognized as a three-place relation, involving all three types of entities (propositions, interpretations, and values) inextricably. However, for many applications the substance of the information in the three-place relation is conveyed well enough by the data of its bounding or derivative two-place relations. | | One relation that is of telling importance is the relation of interpretations to the value they give a proposition. In its full sense and general case this should be recognized as a three-place relation, involving all three types of entities (propositions, interpretations, and values) inextricably. However, for many applications the substance of the information in the three-place relation is conveyed well enough by the data of its bounding or derivative two-place relations. |
− | The interpretations that render a proposition true, i.e. the substitutions for which the proposition evaluates to true, are said to satisfy the proposition and to be its models. With a doubly modulated sense that is too apt to be purely accidental, the model set is the "content" of the proposition's formal expression (Eulenberg, 1986). In functional terms the models of a proposition p are the pre-images of truth under the function p. Collectively, they form the set of vectors in p<sup>–1</sup>(1). In another usage the set of models is called the fiber of truth, in other words, the equivalence class [1]p of the value 1 under the mapping p. | + | The interpretations that render a proposition true, that is, the substitutions for which the proposition evaluates to true, are said to satisfy the proposition and to be its models. With a doubly modulated sense that is too apt to be purely accidental, the model set is the "content" of the proposition's formal expression (Eulenberg, 1986). In functional terms the models of a proposition ''p'' are the pre-images of truth under the function ''p''. Collectively, they form the set of vectors in ''p''<sup>–1</sup>(1). In another usage the set of models is called the ''fiber'' of truth, in other words, the equivalence class [1]<sub>''p''</sub> of the value 1 under the mapping ''p''. |