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Condition / premise / conclusion / closure / Frege: Conditions are not assumptions - many mathematicians are wrong on this point. - Error: to take a thought whose truth is not yet fixed, and to draw conclusions from it. - A premise is actually e.g. "(if C then B)" - then the truth of C may still be open.
Die Grundlagen der Arithmetik Stuttgart 1987
Funktion, Begriff, Bedeutung Göttingen 1994
Logische Untersuchungen Göttingen 1993