I have a question when reading the paper Kisseberth(1970). It’s about when rules can be collapsed. My question is about "adjacent rules". I don't quite understand what "ordered before" and "ordered after" means.
The author says that for rules to be collapsed, not only the structure environment should be similar, the rules also need to be adjacently ordered.
‘That is, if two rules such as (4) and (5) are to be collapsed by standard notational conventions, there must not be some other rule which is ordered after (4) but before (5), or after (5) but before (4). According to the standard theory, the existence of such a rule blocks the collapsing of (4) and (5) into (6) - whatever the degree of structural similarity may be.’
(4)V -> ∅/__ V
(5)V -> ∅/VC[-long]CV
(6)V -> ∅/{ __V
VC[-long]CV}
Thanks for help in advance!