In general the extension of a residually finite group by a residually finite group may not be residually finite. We define a strong form of residual finiteness for groups and show that the property is closed under extensions. We then show how groups with this property can be constructed using amalgamated free products and HNN extensions. This leads to a multitude of examples.
The Journal of Group Theory is devoted to the publication of original research articles in all aspects of group theory. Articles concerning applications of group theory and articles from research areas which have a significant impact on group theory will also be considered.