The formalist point of view maintains that formal derivations underlying proofs, although usually not carried out in practice, contribute to the confidence in mathematical theorems. Opposing this opinion, the main claim of the present paper is that such a gain of confidence obtained from any link between proofs and formal derivations is, even in principle, impossible in the present state of knowledge. Our argument is based on considerations concerning length of formal derivations. Thanks to Jody Azzouni for enlightening discussions concerning (...) the subject of this paper and to anonymous referees whose important remarks permitted us to correct the arguments and improve presentation. The remaining flaws remain, of course, solely the responsibility of the author. This research was partially supported by NSERC discovery grant and by the Research Chair in Distributed Computing at the Université du Québec en Outaouais. CiteULike Connotea Del.icio.us What's this? (shrink)

Chciałem Go pożegnać. Kilkakrotnie próbowałem napisać choć parę słów. O Nim samym. Okazało się, że nie potrafię. Udało mi się tylko przedstawić Jego poglądy na reizm Tadeusza Kotarbińskiego, ale uczyniłem to gdzie indziej. Muszę tu poprzestać na ofiarowaniu Mu tego, co napisałem na Jego dziewięćdziesiąte urodziny, w osiemdziesięciolecie naszej przyjaźni.

Chciałem Go pożegnać. Kilkakrotnie próbowałem napisać choć parę słów. O Nim samym. Okazało się, że nie potrafię. Udało mi się tylko przedstawić Jego poglądy na reizm Tadeusza Kotarbińskiego, ale uczyniłem to gdzie indziej. Muszę tu poprzestać na ofiarowaniu Mu tego, co napisałem na Jego dziewięćdziesiąte urodziny, w osiemdziesięciolecie naszej przyjaźni.

The paper focuses on automation of signal processing, which also considers analysis of biomedical data, such as EEG. The results of the study prove that this enables a better understanding of signal changes and makes it possible to address some specific disturbances. It also makes it possible to describe the relevant changes in signals mathematically and helps to create markers of various brain disorders. This paper presents the study at the initial stage and focuses on the mathematical markers of concentration (...) disorders associated with Theta waves. The presented markers presented are based on Welch’s periodograms. The obtained results are very promising and further studies aimed at refining them are currently being carried out. (shrink)

Chemotherapy is one of the most common treatments used in cancer therapy despite its serious side effects, which remain a huge concern. To the most common side effects include memory and concentration problems as well as changes in taste. This paper presents a very preliminary study focusing on cognitive dysfunction after chemotherapy in breast cancer. This phenomenon, called Cancer-Related Cognitive Dysfunction, is a frequent occurrence. The obtained results prove the impact of chemotherapy on the participant’s ability to concentrate. The QEEG (...) method and digital data analysis were used as the measurement methods. (shrink)

In bioethical discussions of human cloning there are sometimes employed definitions broadening the denotation of the term human being to include also, on an equal footing, human embryos. Also, the fact of being human is being equated with being a person. Consequently, embryos are treated as having dignity and calls are heard in the name of justice to protect the rights and interests of embryos whenever these clash with the interests of mature human beings. The author, being a layman in (...) the area of human cloning, limits himself to indicating views he agrees with and those he finds doubtful. He expects human cloning will be taking place, albeit on a small scale, regardless of any bans which would only force the practice to become clandestine. Arguments in favor of controlled human cloning include not only the need to preserve freedom in scientific research, but also hopes for minimizing the adverse effects of cloning. The author indicates factors of an emotional nature which hamper discussions of cloning. He also argues that objections to experiments with humans and demands to make them conditional on prior consent of the people being experimented on are ineffective and often impossible to satisfy. The author also believes that it is impossible to unconditionally obey the commandment "You shall not kill". He does not see any threats posed by the fact that the clone and the cloned person will be identical. While not overlooking the potential dangers to clones (such as genetic defects), the author also sees potential advantages of cloning and transplantology (therapeutic, psychic, social). (shrink)

An ideal I defined on a group G is called idempotent if for every $A \in I, \{g \in G: Ag^{-1} \not\in I\} \in I$ . We show that a countably complete idempotent ideal on an abelian group cannot be prime but may have strong saturation properties.

Gdy człowiek, który – jak ja obecnie – ma dziewięćdziesiąt jeden lat, rezygnuje z jakiejś działalności, nie musi specjalnie się wysilać, aby usprawiedliwić swą decyzję. Lepiej, by sam wybrał ten moment i uprzedził o tym otoczenie, niżby miała zań zdecydować natura i zaskoczyć zarówno jego, jak innych...

CONTENTS:--Reichenbach, H. Elementy logiki formalnej (fragmenty).--Wybrane studia z semiotyki logicznej.