Since its founding nearly 15 years ago, Sonos has amassed a devoted following among audio enthusiasts for its high-end, WiFi-connected speakers. But now its business is endangered by a new breed of speakers powered by artificial intelligence assistants from the likes of Google and Amazon. They're starting to eat into the company's bottom line. In the midst of that change, Sonos cofounder John MacFarlane is stepping down as CEO after leading the company since 2002. Sonos president Patrick Spence will be taking over as CEO.

After 14 years at the helm, Sonos CEO and co-founder John MacFarlane has stepped down. He has also resigned from the company's board or directors, but will remain with Sonos to work on other projects and serve as a mentor to employees. MacFarlane's transition is the latest in a handful of personnel moves that began last year. Sonos announced layoffs last March shortly before product head Marc Whitten left the company. Former president and chief commercial officer Patrick Spence will take over as CEO.

In this paper, we provide more evidence for the contention that logical consequence should be understood in normative terms. Hartry Field and John MacFarlane covered the classical case. We extend their work, examining what it means for an agent to be obliged to infer a conclusion when faced with uncertain information or reasoning within a non-monotonic, defeasible, logical framework (which allows e. g. for inference to be drawn from premises considered true unless evidence to the contrary is presented).