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Identity/is/analytical/intensional/Mates: it is disputed whether A is A is to be considered as formal analytical or analytical because of the meaning of . - Just as statements of the scheme E.g. If A is warmer than B and B is warmer than C, so A is warmer than C analytically because of the sense of "being warmer than". - The dispute is about whether "is" can be seen as a logical constant as "not", and so on or if it belongs to the non-logical vocabulary. - Language L: here was "is" non-logical. - That was arbitrary.
If non-logical, then independent theory of identity possible. - On the other hand: if "is" logical constant (which always means the relation of identity above this region) we construct with that a new language.
Theory/Mates: is always determined by the amount of their doctrines. - ((S) because these contain the entire non-logical vocabulary.)
Definitions/Mates: are needed to represent formalized theories. - They introduce designations that do not belong to the vocabulary of the language, but which improve readability.
Definition creative Definition/Mates: leads to new theorems in which the defined symbol does not occur. - demand: a satisfactory definition should not be creative.
Elementare Logik Göttingen 1969