  More interestingly, it is standardly accepted that if \(s\) presupposes \(p\) (which itself is presupposition free) then both ‘\(p\) and \(s\)’ and ‘If \(p\) then \(s\)’ are presupposition-free. This prediction accounts for why, even in contexts where participants in the conversations do not accept in advance that Jack was murdered, the following no longer suffer from presupposition failure: 