Existence

A semantics $\sigma$ satisfies Existence iff $\sigma(F) \neq \emptyset$ for every framework $F$ .

Reference

van der Torre, L. & Vesic, S. (2018). The Principle-Based Approach to Abstract Argumentation Semantics. In: Baroni, P., Gabbay, D., Giacomin, M. & van der Torre, L. (eds.), Handbook of Formal Argumentation, Vol. 1, Chapter 16, pp. 797–837. College Publications.