Ring coproducts embedded in power-series rings

Pere Ara, Warren Dicks
2015 Forum mathematicum  
AbstractLetWe prove that ifWe show that α is injective ifThe arguments and results extend easily from two variables to any set of variables.The article concludes with some results contributed by G. M. Bergman that describe situations where α is not injective. He shows that if
doi:10.1515/forum-2012-0170 fatcat:kystbry3c5h6hpzxs4m4w56knm