 This conception of question meanings forms the cornerstone of the most basic implementation of inquisitive semantics, the system \(\Inq_B\) (Groenendijk and Roelofsen 2009, Ciardelli 2009, Ciardelli and Roelofsen 2011, Roelofsen 2013, Ciardelli 2016, Ciardelli et al. 2018). In this system, question meanings are defined as downward closed sets of propositions that together cover the entire logical  space.[1]  We will refer to such sets as inquisitive question meanings.[2]