'Published' means different things to different people. Normally, a common feature is that the work has to have been disseminated or made public. A conference presentation may have been delivered to a gathering of 2000 people, but perhaps 500 hear an oral presentation and only a handful may actually engage with a poster. Opportunities for copying, taking notes etc - lots of countries definitions have different requirements for a work to be considered 'published'.
In the following examples, how do you apply a legal definition of 'published' ?
If you have references to your legal definition, so much the better !