Über das Markov-Prinzip.
Über das Markov-Prinzip II.
Über das Verhältnis zwischen intuitionistischer und klassischer Arithmetik.
Über die mit dem Bar-Rekursor vom Typ 0 definierbaren Ordinalzahlen.
Über ein konstruktives Analogon eines Satzes von K. M. Garg über Ableitungszahlen
Über Hilbert's reale und ideale Elemente.
Über katalogisierte Räume
Über konstruktive Methoden der Galoistheorie.
Über Teilsysteme von ...({g}).
Über zwei Bezeichnungssysteme für Ordinalzahlen.
Un anneau de Prüfer
Let be the ring of integer valued polynomials over . This ring is known to be a Prüfer domain. But it seems there does not exist an algorithm for inverting a nonzero finitely generated ideal of . In this note we show how to obtain such an algorithm by deciphering a classical abstract proof that uses localisations of at all prime ideals of . This confirms a general program of deciphering abstract classical proofs in order to obtain algorithmic proofs.
Una teoria-quadro per i fondamenti della matematica
We propose a "natural" axiomatic theory of the Foundations of Mathematics (Theory Q) where, in addition to the membership relation (between elements and classes), pairs, sets, natural numbers, n-tuples and operations are also introduced as primitives by means of suitable ground classes. Moreover, the theory Q allows an easy introduction of other mathematical and logical entities. The theory Q is finitely axiomatized in § 2, using a first-order language with a binary relation (membership) and five...
Undecidability vs transfinite induction for the consistency of hyperarithmetical sets.
Une démonstration du théorème de complétude de Godel
Un'estensione del teorema di Löb
Unimodular rows over Laurent polynomial rings
We prove that for any ring of Krull dimension not greater than 1 and , the group acts transitively on . In particular, we obtain that for any ring with Krull dimension not greater than 1, all finitely generated stably free modules over are free. All the obtained results are proved constructively.
Unsolvable systems of equations and proof complexity.