When making easy decisions, we keep the consistency among candidate relations by making use of constraints (i.e., domain and uniqueness constraints) to eliminate conflicts directly, instead of implicitly encoding constraints in ILP (Yao et al., 2010;de Lacalle and Lapata, 2013;Chen et al., 2014a;Koch et al., 2014;Chen et al., 2014b).
the number of variables and constraints to be encoded in ILP is significantly reduced, which speeds up the entire decision making process.