|Similarity: conformity of one or more - but not all - properties of two or more objects.|
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Meaning equality/equality of meaning/logic/Termini/Wessel: if two simple terms have the same meaning, they are also the same in sense, and vice versa, but the converse is not true for composite Termini - E.g. "rhombus", "equilateral rectangle": same meaning, but not the same sense if the second composed - reason: the logical structure is not always coincident with the language - Morgenstern/Wessel: can be interpreted as a composite term: then, because morning and evening different meaning, the sense of compound Termini is different.
Logik Berlin 1999