The two readings can be thought of as resulting respectively from scoping his boss first, then filling in the elided material, and the reverse ordering of these operations (Dalrymple et al. 1991; see also Crouch 1995; Gregory and Lappin 1997). Other challenging forms of ellipsis are event ellipsis, as in (5.3) (where forgot stands for forgot to bring), entirely verbless sentences such as (5.4) and (5.5), and subjectless, verbless ones like (5.6) and (5.7):