Computational language: week 9 Finish finite state machines FSA’s for modelling word structure Declarative language models knowledge representation and inheritance non-monotonic or ‘default’ inheritance and lexical knowledge representation multiple inheritance DATR: a lexical knowledge representation language
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Computational language: week 9 Finish finite state machines FSA’s for modelling word structure Declarative language models knowledge representation and.
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Computational language: week 9 Finish finite state machines
FSA’s for modelling word structure Declarative language models
knowledge representation and inheritance non-monotonic or ‘default’ inheritance and
lexical knowledge representation multiple inheritance DATR: a lexical knowledge representation
language
Finite State Automata Deterministic FSAs
An FSA whose recognition behaviour is fully determined by the state it is in and the input symbol it is looking at
Finite State Automata Deterministic FSAs
An FSA whose recognition behaviour is fully determined by the state it is in and the input symbol it is looking at
Non-deterministic FSAs An FSA with decision points
Finite State Automata Deterministic FSAs Non-deterministic FSAs
An FSA with decision points Self-loop may be in a particular state Arcs may have ε transitions
Finite State Automata Formal language Set of strings Finite symbol set, alphabet
Finite State Automata Formal language Set of strings Finite symbol set, alphabet L(m) = {baa!, ba!, baaa!,…}“formal language characterised by m”
m = model L = formal language
Finite State Automata Formal language Set of strings Finite symbol set, alphabet L(m) = {baa!, ba!, baaa!,…} A formal language models a
fragment of a natural language
Finite state transducers and word structure FSA for word structure
Handles the morphotactics Arc labels drawn from sets of lexical
classes Lexical entries and affixes in the
lexicon Achieve morphological recognition
Finite state transducers and word structure Finite State Transducers for
morphological parsing distinction between surface level and lexical level
lexical level includes basic stem and morphosyntactic features
cat +N+PL -> cats
Finite state transducers and word structure Finite State Transducers for
morphological parsing distinction between surface level and lexical level
lexical level includes basic stem and morphosyntactic features
cat +N+PL -> cats FST: maps one of set of symbols onto
another
Finite state transducers and word structure Finite State Transducers for
morphological parsing distinction between surface level and lexical
level lexical level includes basic stem and
morphosyntactic featurescat +N+PL -> cats FST: maps one of set of symbols onto
another c:c a:a t:t +N:εPL:s
Finite state transducers and word structure Finite State Transducers for
morphological parsing Boundary markers:
^ morpheme boundary # word boundary
Finite state transducers and word structure Finite State Transducers for
morphological parsing Boundary markers:
^ morpheme boundary # word boundary
c:c a:a t:t +N:εPL:^s#
Finite state transducers and word structure Finite State Transducers for