(26a) vs. (26b) below:7 Compl X Compl X (a) Specifier on the left (b) Specifier on the right It turns out there is a considerable difference both in terms of the number of LR actions performed and the stack depth required to process an example like formalize, analyzed as formal-i(z)-e in (27) below:  7Two other specifier-head-complement configurations can be obtained.
we fix the head as being to the right of the complement for reasons of linearization.