Characterizations of Regularity
Department of Mathematics
University of Turku, Finland
Regular languages have many different characterizations
in terms of automata, congruences, semigroups etc.
In this talk we have a look at the more recent result,
obtained during the last two decades, namely
characterizations using morphic compositions,
equality sets and well ordered structures.
Finnish Optimality-Theoretic Prosody
Palo Alto Research Center
A well-known phenomenon in Finnish prosody is the alternation of binary
and ternary feet. In native Finnish words, the primary stress falls on
the first syllable. Secondary stress generally falls on every second
'gymnasts' creating a sequence of trochaic binary feet. However,
secondary stress skips a light syllable that is followed by a heavy
syllable. In (vói.mis.te).(lèm.me)
'we are doing gymnastics', the first foot is ternary, a dactyl.
Within the context of Optimality Theory (OT, Prince and Smolensky
1993), it has been argued that prosodic phenomena are best explained in
terms of universal metric constraints. OT constraints can be
violated; no word can satisfy all of them. A language-specific
ranking of the constraints makes some violations less important than
others. In her 1999 dissertation, A
unified account of binary and ternary stress, Nine Elenbaas
gives an analysis of Finnish in which the alternation between binary
and ternary feet follows as a side effect of the ordering of two
particular constraints, *Lapse
and *(L'. H) The *Lapse
constraint stipulates that an unstressed syllable must be adjacent to a
stressed syllable or to word edge. The *(L'. H) constraint prohibits feet
such as (tè.lem) where
a light stressed syllable is followed by a heavy unstressed
syllable. The latter constraint of course is outranked by the
constraint that requires initial stress on the first syllable in
Finnish regardless of the its weight. In his 2003 article on Finnish Noun Inflection, Paul
Kiparsky gives essentially the same account of the binary/ternary
alternation except that he replaces the *(L'.H) rule by a more general StressToWeight constraint.
Although OT constraints themselves can be expressed in finite-state
terms, Optimality Theory as a whole is not a finite-state model if it
involves unbounded counting of constraint violations (Frank and Satta
1998). With that limitation OT analyses can be modelled with
finite-state tools. In this paper we will give a full computational
implementation of the Elenbaas and Kiparsky analyses using the extended
regular expression calculus from the 2003 Beesley & Karttunen book
on Finite State Morphology.
Surprisingly, it turns out that Elenbaas and Kiparsky both make some
incorrect predictions. For example, according to their accounts a word
such as kalasteleminen
'fishing' should begin with a ternary foot: (ká.las.te).(lè.mi).nen.
The correct footing is (ká.las).(tè.le).(mì.nen).
There may of course be some ranking of OT constraints under which the
binary/ternary alternation in Finnish comes "for free". It does not
emerge from the Elenbaas and Kiparsky analyses.
This case study illustrates a more general point: Optimality Theory is
computationally difficult and OT theorists are much in the need of