Full Idea
It is no part of supervenience that 'if p then q' entails 'if not p then not q'. To avoid such misunderstandings, it is common (though not more accurate) to describe supervenience in negative terms: no difference in A without a difference in B.
Gist of Idea
To avoid misunderstandings supervenience is often expressed negatively: no A-change without B-change
Source
Francesco Orsi (Value Theory [2015], 5.2)
Book Reference
Orsi,Francesco: 'Value Theory' [Bloomsbury 2015], p.82
A Reaction
[compressed] In other words it is important to avoid the presupposition that the given supervenience is a two-way relation. The paradigm case of supervenience is stalking.