301 research outputs found
A Proof-Theoretic Approach to Scope Ambiguity in Compositional Vector Space Models
We investigate the extent to which compositional vector space models can be
used to account for scope ambiguity in quantified sentences (of the form "Every
man loves some woman"). Such sentences containing two quantifiers introduce two
readings, a direct scope reading and an inverse scope reading. This ambiguity
has been treated in a vector space model using bialgebras by (Hedges and
Sadrzadeh, 2016) and (Sadrzadeh, 2016), though without an explanation of the
mechanism by which the ambiguity arises. We combine a polarised focussed
sequent calculus for the non-associative Lambek calculus NL, as described in
(Moortgat and Moot, 2011), with the vector based approach to quantifier scope
ambiguity. In particular, we establish a procedure for obtaining a vector space
model for quantifier scope ambiguity in a derivational way.Comment: This is a preprint of a paper to appear in: Journal of Language
Modelling, 201
Vector spaces as Kripke frames
In recent years, the compositional distributional approach in computational
linguistics has opened the way for an integration of the \emph{lexical} aspects
of meaning into Lambek's type-logical grammar program. This approach is based
on the observation that a sound semantics for the associative, commutative and
unital Lambek calculus can be based on vector spaces by interpreting fusion as
the tensor product of vector spaces.
In this paper, we build on this observation and extend it to a `vector space
semantics' for the \emph{general} Lambek calculus, based on \emph{algebras over
a field} (or -algebras), i.e. vector spaces endowed
with a bilinear binary product. Such structures are well known in algebraic
geometry and algebraic topology, since they are important instances of Lie
algebras and Hopf algebras. Applying results and insights from duality and
representation theory for the algebraic semantics of nonclassical logics, we
regard -algebras as `Kripke frames' the complex algebras of which
are complete residuated lattices.
This perspective makes it possible to establish a systematic connection
between vector space semantics and the standard Routley-Meyer semantics of
(modal) substructural logics
Classical BI: Its Semantics and Proof Theory
We present Classical BI (CBI), a new addition to the family of bunched logics
which originates in O'Hearn and Pym's logic of bunched implications BI. CBI
differs from existing bunched logics in that its multiplicative connectives
behave classically rather than intuitionistically (including in particular a
multiplicative version of classical negation). At the semantic level,
CBI-formulas have the normal bunched logic reading as declarative statements
about resources, but its resource models necessarily feature more structure
than those for other bunched logics; principally, they satisfy the requirement
that every resource has a unique dual. At the proof-theoretic level, a very
natural formalism for CBI is provided by a display calculus \`a la Belnap,
which can be seen as a generalisation of the bunched sequent calculus for BI.
In this paper we formulate the aforementioned model theory and proof theory for
CBI, and prove some fundamental results about the logic, most notably
completeness of the proof theory with respect to the semantics.Comment: 42 pages, 8 figure
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