The search session has expired. Please query the service again.

The search session has expired. Please query the service again.

The search session has expired. Please query the service again.

The search session has expired. Please query the service again.

Displaying 161 – 180 of 1467

Showing per page

On almost normal subgroups of supersoluble groups

Carmela Musella (1999)

Bollettino dell'Unione Matematica Italiana

Un sottogruppo H di un gruppo G si dice «almost normal» se ha soltanto un numero finito di coniugati in G , e ovviamente l'insieme a n G costituito dai sottogruppi almost normal di G è un sottoreticolo del reticolo L G di tutti i sottogruppi di G . In questo articolo vengono studiati gli isomorfismi tra reticoli di sottogruppi almost normal, provando in particolare che se G è un gruppo supersolubile e G ¯ è un gruppo FC-risolubile tale che i reticoli a n G e a n G ¯ sono isomorfi, allora anche G ¯ è supersolubile, e...

On an algorithm to decide whether a free group is a free factor of another

Pedro V. Silva, Pascal Weil (2008)

RAIRO - Theoretical Informatics and Applications - Informatique Théorique et Applications

We revisit the problem of deciding whether a finitely generated subgroup H is a free factor of a given free group F . Known algorithms solve this problem in time polynomial in the sum of the lengths of the generators of H and exponential in the rank of F . We show that the latter dependency can be made exponential in the rank difference rank ( F ) - rank ( H ) , which often makes a significant change.

On an algorithm to decide whether a free group is a free factor of another

Pedro V. Silva, Pascal Weil (2007)

RAIRO - Theoretical Informatics and Applications

We revisit the problem of deciding whether a finitely generated subgroup H is a free factor of a given free group F. Known algorithms solve this problem in time polynomial in the sum of the lengths of the generators of H and exponential in the rank of F. We show that the latter dependency can be made exponential in the rank difference rank(F) - rank(H), which often makes a significant change.

Currently displaying 161 – 180 of 1467