A Semantic Characterization of Locative PPs

A Semantic Characterization of Locative PPs

To appear in proceedings of SALT7

Joost Zwarts Yoad Winter

Utrecht Institute of Linguistics OTS

1Introduction

The last two decades have seen remarkable development in compositional mod-eltheoretic semantics of natural language.The idea that natural language expres-sions can be directly interpreted in the model of discourse has gained signi?cant support in various domains.It led to a better understanding of inference in lin-guistics with close relation to syntax,helped to characterize linguistically relevant classes of expressions,and revealed systematic constraints on their possible mean-ings.Quite independently of these developments,much work in the?elds of cogni-tive and conceptual semantics has acquired a signi?cant body of knowledge about the semantic behaviour of prepositional phrases(PPs).In the modeltheoretic frame-work,however,the semantics of PPs has remained,to a large extent,unexplored. Our aim in this paper is to contribute for bridging this gap.

We re?ne and extend the proposal in Zwarts(1995),arguing for a vector space as the underlying ontology in the compositional analysis of locative PP struc-tures.In section2we introduce a general semantic framework that uses such a model.Section3studies some denotational properties of prepositions in the pro-posed system.Certain properties introduced in Zwarts(1995)will be placed here in a wider perspective of preposition monotonicity.Two notions of monotonicity are de?ned and shown to be linguistically relevant in restricting the set of possible preposition denotations,accounting for central inferences and affecting grammat-icality of modi?ed PPs.An additional constraint,similar to the conservativity re-striction on determiners,is shown to hold of natural language locative prepositions.

Throughout this paper,we presuppose familiarity with basic Linear Algebra and simple notions from Topology.Some useful de?nitions are summarized in an appendix.

2Vector Semantics of Locative PPs

Sentences with spatial uses of prepositions show inferential regularities that are comparable with the much studied inferences with quanti?ed expressions.For in-stance,like the determiner every,the preposition inside is transitive,in the sense illustrated in(1).The preposition near is symmetric similar to the determiner some, as exempli?ed in(2).

(1)A is inside B every A is B

B is inside

C every B is C

A is inside C every A is C

(2)

A is near

B some A is B

B is near A some B is A

As far as determiners concern,this kind of observations about inferences is the

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empirical basis for the generalized quanti?er semantics of the noun phrase.That prepositions show similar consistencies is a reason to develop also a modeltheo-retic semantics of the prepositional phrase,with a similar research agenda to the one of generalized quanti?er theory(see e.g.Keenan(1996)).

2.1A preliminary typology of spatial prepositions

The preposition is the most useful syntactic category in natural languages for ex-pressing statements about space and movement.Locative prepositions are used to locate an object relative to another one,the reference object.For instance,in the predicative constructions(3a/b)the house is the reference object and the tree is the located object.Directional prepositions are more“dynamic”than the locative ones: they are usually connected to a verb or a noun expressing movement or direction as in(4a).Unlike the locative ones,the directional prepositions often resist predicative constructions(cf.(4b)).

(3)a.The tree is outside the house.

b.The tree is behind the house.

(4)a.John walked to the park.

b.?John is to the park.

We concentrate on the locative prepositions and PPs,which can be classi?ed into projective and non-projective.A non-projective preposition like outside in(3a) requires only spatial knowledge on the location of the two objects.By contrast,the projective preposition behind requires further information about directions from the reference object.To determine whether(3b)is true,the shape and location of the tree and the house are not suf?cient.Also the back side of the house should be determined.This can change with the position of the speaker or conventions of using the house and hence it is not only a function of its intrinsic spatial properties. These distinctions(cf.Herskovits(1986))are further exempli?ed in(5)-(6).

(5)Locative prepositions:

a.Projective:above,below,in front of,behind,beside

b.Non-projective:in/inside,outside,on,at,near,between

(6)Directional prepositions:to,from,into,onto,across,around,through

2.2The modi?cation problem

Many locative PPs can be modi?ed by expressions that involve some measure of distance or direction.For example,in addition to the“bare”PP structures of(3), there are also modi?ed structures as in(7).Some other cases of PP modi?cation are exempli?ed in(8).

(7)a.The tree is ten meters[outside the house].

b.The tree is ten meters[behind the house].

(8)diagonally above the door,far outside the city,right in front of the car

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These structures are classi?ed as PP modi?cation because the additional expression syntactically applies to a PP(or a P-bar)to produce another PP(P-bar).Zwarts (1995)discusses the problem of giving a compositional semantics to such struc-tures.Previous works(e.g.Wunderlich(1991)a.o.)propose to treat prepositions as relations between sets of points(regions).A region is outside a region iff the two regions are https://www.wendangku.net/doc/d88122274.html,positionally,outside denotes a function mapping a region to the set of regions disjoint to it:outside.This predicate over regions compositionally applies to:outside.Suppose now that in(3a)and in(7a)the house occupies a region and the tree occupies a region consisting of a single point.The analysis of(3a)is straightforward and tantamount to.In order to analyze compositionally also(7a),the denotation of the modi?er ten meters should apply to the denotation of outside.To get the correct semantics,this function has to measure the distance between and.But this is problematic,as is not directly speci?ed in the set outside.One may try to approach the problem by reproducing from this set(e.g.observing that is the complement of outside).However,the same ad hoc procedure would not correctly hold of(7b).A general compositional treatment of PP modi?cation is not forthcoming if locative prepositions are taken as relations between sets of points.

Zwarts(1995)makes the following observations.Modi?ers like ten meters and diagonally are predicates over distance and direction respectively.Hence also the function that a locative preposition denotes should return entities with measur-able distance and direction.These entities are proposed to be vectors:directed line segments between points in space.Assume that an expression like outside the house denotes a set of vectors:roughly,the ones pointing outwards from the boundary of the house.Cases of syntactic modi?cation as in(7)-(8)are naturally analyzed as (intersective)semantic modi?cation:a PP modi?er is a function that maps any set of vectors to one of its subsets.For instance,ten meters maps a set of vectors to its subset containing only vectors that are ten meter long:. Thus,ten meters outside the house denotes the set of ten meter vectors pointing out-wards from the house.A locative preposition then denotes a function that applies to the set of points where the reference object is located and returns a set of vectors. The next section substantiates this proposal.

2.3Vector space ontology

A natural way to implement the proposal in Zwarts(1995)is to assume that vec-tors are the primitive spatial entity in models of natural language.Space ontology consists of a vector space over the real numbers.The element is the zero vector and the functions and are vector addition and scalar multiplication respectively.We assume a positive scalar prod-uct,standardly de?ning a norm.It is further assumed that is an Euclidean n-space.Drawing on this ontology,we de?ne the domain of oints and the domain of ectors.is simply identi?ed with .Intuitively,each vector in uniquely determines its end-point and vice versa. The domain is de?ned as the cartesian product.Each“point”in

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(=a vector in)functions as“the center”(=the zero vector)of a vector space .This is done as in the following de?nition.

De?nition1(the vector domain)Let be a vector space over with a positive scalar product and.We de?ne:

For all:

For all,:

For all:

For every:is a vector space over with a positive scalar product,which determines a norm denoted by.Trivially,the domain

is equal to the union of vector spaces.

Notational conventions(see?g.1a):for points;

for vectors;if then s-point is the start-point of, e-point is its end-point.The vectors and can be viewed as“points”and in.We sloppily use the symbols and for operators on members of,without mentioning the subscript as strictly required.and

respectively.

are treated as typed domains of types and

Figure1:

2.4The compositional process

Reconsider the modi?ed structures in(7).The proposed“semantic structure”of a modi?ed PP with a modi?er MOD,a preposition P and a reference object region REF is as follows:

MOD(P(REF))

The assumed denotation of a measure phrase modi?er MOD is straightforward(un-like the analysis of its compositional semantics).For instance:

The denotations of various locative prepositions for P will be de?ned in the next section.The region REF is determined by the denotation of the-type reference object.A location function assigns any physical entity in its location in space,or eigenspace(Wunderlich(1991)).Since a PP basically denotes a set of vectors,we have to translate it into an“ordinary”predicate that stan-dardly applies to the subject of predication(the located object).An“anti-location”function returns the objects at the region determined by the set of vectors:

loc e-point

In words:loc maps any set of vectors to the set of entities whose eigenspace is contained in the set of’s end-points.

To exemplify the process,sentence(7a)denotes the following proposition.

(9)

Figure2:

For example,in?gure2a:is external to,is internal to,and and are neither internal nor external to.Zero vectors in the boundary of are considered internal to.

De?nition3(externally/internally closest vectors)A vector is externally (internally)closest to a set of points iff is external(internal)to and for every vector that is external(internal)to s.t.e-point e-point: .In case this holds we denote().

De?nition3imposes a condition of minimality:it classi?es vectors external/internal to a set of points that are the shortest vectors connecting points in’s boundary to points outside/inside.This condition is required because of the semantics of PP modi?cation.For example,a point as in?gure2b can be said to be exactly three meters outside the box only if the shortest vector connecting it to the box, ,is three meters long.Longer connections like are irrelevant.In a similar way,is not diagonally above the box although is a vector diagonal to the box. Correspondingly,while the vector is de?ned as externally closest to,is not.

Under the topological simplicity assumption these notions are related to the intuitive de?nition of external/internal points using set membership.Consider?rst the following topological property(see Wall(1972:p.18)):

Proposition1If and are disjoint closed subsets of and is compact, then,the distance between and,which is de?ned by the in?mum

,is positive.

By this property,we can show the following correspondence:

Proposition2Let be a non-trivial closed set in(=).Then for every point the following conditions are equivalent:(a)There is a vector

that is externally(internally)closest to s.t.e-point.(b)() Proof:directly by the de?nition of external/internal vectors.Let us show .

1.Assume.is bounded and closed in,hence compact.Thus by proposition1,.Let be a closed sphere around of radius .

Let us show.Assume by negation.By de?nition of:

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for every there is s.t..The line segment intersects,the boundary of,at point.Thus,.is closed,hence,so.

Conclusion:.But is bounded and closed in,hence compact.By our assumption.Thus by proposition1,.Contradiction.

We conclude that.It is easy to show.Thus,for any ,the vector from to satis?es. Therefore,is externally closest to with e-point.

2.Assume.trivially holds if:the zero vector from to is internally closest to.For is in the interior of,,repeat the above proof for and(a closed set)and note that.

Consider?rst the prepositions in/inside and outside.In our proposal they map a set of points to the set of its internally/externally closest vectors respectively. Thus,we simply de?ne:

(10)in,inside:

outside:

The compositional procedure and proposition2guarantee that these de?ni-

tions coincide with the intuition that inside and outside correspond to set contain-ment and disjointness,respectively.

Corollary3Let the eigenspace loc(a)of an object a be a non-trivial closed set. Then the following holds:1.b is inside a is true iff 2.b is outside a is true iff.

This seemingly trivial result shows that the vector semantics of prepositions like outside,designed to deal with their allowing for PP modi?cation,still preserves the basic set-theoretical intuition of the point semantics.The achievement of both goals is not trivial.

All prepositions except inside give rise to regions that are outside the eigen-space,so the relation is a part of their de?nition.The preposition imposes an additional condition on the vector.This condition can involve the length,as in the following de?nitions:

(11)on,at:

near:

where and two small positive numbers and

We interpret on and at as requiring almost zero distance between the objects.In the case of near the vector’s length is said to be smaller that a pragmatically determined number.

The prepositions between and amid require two or more reference objects. We de?ne as corresponding to a non-constituent expression between... and....A more adequate treatment requires an analysis of plurality.The function maps two regions and to a set of vectors using the region,

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a. b. c.

Figure3:

the convex hull of.For regions and as in?gure2c,is the set of vectors that are externally closest to or to whose end-point is in the shaded region.

(12)between...and...:

e-point

As mentioned,the projective prepositions presuppose certain directions in space.We assume that this is pragmatically determined using three orthogonal unit vectors in for up,right and front,which are called axes.For every start-point of vectors in,an axis determines an axis that we denote.

Consider the projective preposition above.The region this preposition gen-erates when the reference object is a single point is illustrated in?gure3a.The above-region consists of those vectors that make an acute angle with the up()axis. Thus,above allows only vectors whose vertical component(on up)is larger than their projection on the orthogonal component(=the horizontal plane).This is de?ned using the following fact from linear algebra(see https://www.wendangku.net/doc/d88122274.html,ng(1977:p.134)). Proposition4For every where there is a unique scalar

and a unique vector s.t..The scalar is called’s component along and the vectors and are called’s projection on and on respectively.

For a vector and an axis,we denote

and.The denotations of above and below are de?ned in(13). Other projective prepositions as in(14)work in a similar way but with other axes.

(13)above: below:

(14)

in front of:

2.6Example:transitivity of’between’

The compositional mechanism and the lexical de?nitions above allow a correct analysis of many simple inferences.A central one is the transitive behaviour of between:

(16)A is between B and C D is between A and B

De?nition4characterizes the monotonicity of a prepositional function on the set of points argument.

De?nition4(point monotonicity)Let be a prepositional function and .

1.is upward point-monotone over(PMON)iff

.

2.is downward point-monotone over(PMON)iff

.

We specify point-monotonicity of prepositions according to the behaviour of their denotation over the domain of topologically simple regions.Intuitively,point-monotonicity corresponds to truth preservation under enlargement/diminution of the reference object.For instance,knowing that Paris is in France,we may conclude that both(17a)and(17b)hold.

(17)a.The house is in Paris The house is in France

b.The house is outside France The house is outside Paris

This suggests that in and outside are PMON and PMON prepositions respec-tively.The functions and verify this over the domain of topo-logically simple regions and establish entailments(17a-b).Generally,the inference schemes below characterize the point-monotonicity of a preposition P.

(18)P PMON:P PMON: A is inside B A is inside B C is P A C is P B

C is P B C is P A

Other prepositions besides inside and outside are not point-monotone.Consider the preposition above for example.In?gure3c the sentence the bird is above the house is true,assuming that the bird is and the house is.However,the same sentence is false when we consider a much smaller house or a much larger house .Hence,above is neither downward nor upward point-monotone.We propose the following universal.

Universal1Only and are possible PMON and PMON deno-tations,respectively,for simple locative prepositions in natural language. Consider the expression far from in English.The corresponding prepositional func-tion is PMON but different than the meaning of outside.Universal1claims that this function is not a possible denotation for single word locative prepositions in any natural language.Note that far from in English is neither simple nor evidently locative.It is a compound(not necessarily constituent),derived from the directional preposition from.Unlike far from,a non-PMON preposition like near is realized as a single lexical morpheme in many languages.

Another example for meanings of prepositions that are ruled out by univer-sal1are the following functions,sensitive to the diameter of the reference object. Recall the diameter of a set is the supremum of the set.

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iff and

iff and

These functions are PMON and PMON respectively,but different than

and.

The prepositions outside and inside are special in another respect.By propo-sition2,over topologically simple objects and coincide with set complementation and identity respectively:for every topologically simple:

or .

In other words,for every preposition P either(19a)or(19b)must hold.

(19)a.A is P B A is outside B b.A is P B A is inside B

Thus,the meaning of inside is the only preposition meaning that does not entail outside.This eliminates prepositions that entail inside but are not entailed by it.For instance,an imaginable preposition*nearin satis?es A is nearin B iff A is inside B and A is close to B’s edge.This preposition does not satisfy universal2and is unexpected to occur in any natural language.Also prepositions that entail neither inside nor outside are eliminated.For instance,a preposition equivalent to either near or else inside is ruled out.These predictions are correct as far as we know.

Most prepositions are not point-monotone.A weaker property,however, holds of all prepositions:

De?nition5(point continuity)Let be a prepositional function and. is point continuous over(PCON)iff

.

Point monotonicity entails point continuity.Intuitively,a point continuity test is one that can be called the“Babushka inference”.Suppose that Babushka1is inside Babushka2,which is inside Babushka3.The following inference holds of the PCON preposition beside:

(20)The ball is beside Babushka1and beside Babushka3

The ball is beside Babushka2

We claim that the same holds of all prepositions.

Universal3All prepositions in natural language are point continuous.

This universal is similar to the continuity universal of Thijsse(1983)on“simple”NPs(universal U6of Barwise and Cooper(1981)).Thus,continuity holds of de-terminers and prepositions alike.Universal3rules out an imaginable preposition *aboven that satis?es A is*aboven B iff A is an even number of meters above B. Another example for a non-PCON prepositional function is the following:

iff and is an even natural num-ber

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3.2Vector monotonicity

Prepositional functions are relations between sets of points and vectors.The fol-lowing partial order on allows us to examine their monotonicity with respect to the vector argument.

De?nition6(vector order)For all:iff there is in s.t.

.

Intuitively,is a relation of lengthening over non-zero vectors that have the same start point.For such vectors iff and point in the same direction and.

De?nition7(vector monotonicity)Let be a prepositional function and .

1.is upward vector-monotone over(VMON)iff

.

2.is downward vector-monotone over(VMON)iff

.

Vector monotonicity corresponds to truth preservation when the located object gets further from/closer to the reference object.For instance,when Mary is between the tree and the house,both(21a)and(21b)hold.This suggests that behind is both VMON and VMON.

(21)a.Mary is behind the house The tree is behind the house

b.The tree is behind the house Mary is behind the house

Generally,the following inferences indicate vector monotonicity of a preposition P.

(22)P VMON:P VMON:

A is between

B and

C A is between B and C

A is P C

B is P C

B is P

C A is P C

An example for a non-VMON preposition is near:if A is near B and gets further from it,at a certain point it will no longer be near B.More examples are given below.

(23)VMON:in front of,behind,above,below,beside,outside

not VMON:near,on,at,in/inside,between

Examples for prepositions that are not VMON are harder to?nd.The expression far from could be considered a possible candidate.However,for similar reasons to the aforementioned,we do not take this as a counter-example to the following universal from Zwarts(1995).

Universal4All simple locative prepositions in natural language are VMON.

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Also the arti?cial preposition*not to not from,with the obvious se-mantics,is not VMON.Unlike far from it is not VMON either.

V-monotonicity is relevant to the grammaticality of PP modi?cation.Con-sider the contrast between(24)and(25)vis-`a-vis the VMON properties in(23).

(24)a.two meters in front of/behind/above/below the car

b.?two meters beside the car

c.two kilometers outside the village

(25)a.*two meters near/on/at the house

b.*two meters in/inside the house

c.*two meters between the two houses

Observing this compatibility,Zwarts(1995)proposes that modi?cation of a PP us-ing a measure phrase modi?er is legitimate if and only if the PP is headed by a VMON preposition.Consider,however,sentence(26)in contrast to(25b). (26)The nail is10cm inside the wall.

Modi?cation in(26)is allowed although inside is not VMON.Nevertheless,there is a possible contrast between the eigenspaces that are likely to correspond to the reference objects in the the two cases.We speculate that a wall as in(26)can be conceived of as an“unbounded”object:from the point of view of a person on one of its sides,a wall might have been unbounded on the other side.This is unlikely to be the case with the eigenspace of the house in(25b).Thus,we propose that the relevant property is not vector monotonicity of the preposition,but rather monotonicity of the set of vectors being modi?ed.This is stated as follows. (27)Modi?cation Generalization:A structure[P NP]can be modi?ed by a mea-

sure phrase iff its denotation is VMON:

.

If P is a VMON preposition then,according to(27),modi?cation should be pos-sible for every possible reference object.This accounts for the acceptability of the cases in(24).For non-VMON prepositions and bounded reference objects,(27) expects modi?cation to be impossible,which accounts for(25).However,with in-side and an unbounded reference object as in(26)we still have a VMON set of vectors,although the preposition itself is not VMON.Thus(27)describes also the acceptability of(26).But what can be an explanation for the rule of thumb in(27)? Assume that measure phrase modi?cation is possible iff every non-trivial measure phrase maps to a non-empty set.By universal4,must be VMON.Thus,it is suf?cient to require that is VMON(and non-empty)in order to guarantee this non-emptiness condition.We propose that this semantic requirement is grammati-cized to affect the acceptability of modi?ed PPs.In other words,(27)plus universal 4make sure that non-trivial measure phrases are semantically effective in the mod-i?cation process of the PP.For instance,a PP like*5000km near the house is not simply ungrammatical,but also semantically absurd if its meaning is computed.See Barwise and Cooper(1981:p.183)for a similar reasoning about relations between semantic properties of determiners and grammaticality of there sentences.

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3.3Preposition conservativity

In the proposed system there is an important relation between the two arguments of locative prepositions.Consider the following property.

De?nition8(preposition conservativity)A prepositional function is called con-servative(CONS)iff s-point.

A preposition is called conservative iff its denotation is conservative in every model. In a way that is similar to determiner conservativity,when is a conservative prepositional function the argument restricts the set of possible elements in: only vectors whose start-point is in can be in.We propose:

Universal5All natural language locative prepositions are conservative.

This claim is related to the following inference.

(28)A is meters P B The distance between A and B is meters

All the prepositions discussed above are conservative.(28)holds of all these prepo-sitions when modi?cation is grammatical.Consider,however,an arti?cial non-conservative preposition*behose(=behind something close to),whose denotation is naturally de?ned as follows:

iff

e-point

This is a non-conservative preposition,which is VMON and VMON like behind. Thus,modi?cation by measure phrases should be syntactically possible.However, (28)does not hold of this preposition.An object A can be3meters behind some-thing close to B without the distance between A and B being3meters.Universal5 expects prepositions equivalent to*behose to exist in no natural language.Below we mention another such non-preposition*inose,similarly de?ned as equivalent to inside something close to.

Like conservativity in the determiner domain,also preposition conservativ-ity imposes a reduction in the number of possible denotations for lexical preposi-tions.To get an impression of that,let us tentatively assume that is?nite and,and that and.That is,is the set of vectors over the points in.Let us denote. Proposition6

Proof:by de?nition.

Thus,.

s-point

Let be of cardinality.Thus,the set s-point(the vectors in with start point in)is of cardinality.Therefore we get:

s-point

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(–the number of subsets of of cardinality) 65,53651265,536256

3

Already in a domain with4elements,D-conservativity eliminates more denotations than P-conservativity,although in this case the total number of preposition and de-terminer denotations is the same.Note,however,that CONS is not the strongest restriction we can obtain when also spatial properties are considered.On its own, it is not suf?cient to guarantee the sound inference(28).In fact,if holds then s-point is not just any point in,but rather a member of’s boundary that is closest to e-point.Measuring the reduction in possible prepositions that this spatial property imposes is much harder than with the set-theoretical property CONS,so we must leave this question aside for the time being. Recapitulation Note that the universals1-5are independent.This can be shown by verifying that each of the arti?cial prepositions outside/inside, nearin,outside,not to not from,and inose is ruled out only by the corresponding universal.

Appendix:some useful de?nitions

A vector space over the?eld of real numbers is a quadruple s.t.

is a set,(the zero vector)and the functions(vector addition)and(scalar multiplication)satisfy for all

and:

1.

2.

3.There is an element s.t.

4.

5.

15

6.

7.

8.1v=v(1is the unit element of)

A scalar product over a vector space is a function that satis?es for all:

1.

2.

3.

A scalar product is called positive iff for every:and for every

:.For a positive scalar product the norm of a vector is denoted

factors,the bicycle is near the house is OK whereas the house is near the bicycle is a weird sentence.Similar asymmetries hold for https://www.wendangku.net/doc/d88122274.html,pare for instance some people are politicians with some politicians are people.

3.Of course,in English there are non-spatial prepositions(e.g.before,of)and most spatial prepositions can also be used for expressing non-spatial statements(e.g. Mary arrived on

is a singleton.Changing the de?nition of so that(9)expresses existential quan-ti?cation would be more problematic.For instance,(3a)would become true even if only a tip of one leaf of the tree is outside the house.

7.We do not distinguish between in and inside despite some distributional differ-ences between them(e.g.in the air vs.*inside the air).We also ignore the intricate meaning aspects of in discussed in Herskovits(1986)and Vandeloise(1991).For example,why do we say in the?eld but not in the prairie?Why don’t we usually use the expression in the bowl when a bowl is upside down?Henceforth we put these questions aside,focusing on the more general semantic issues.

8.Again,we are only interested in the general idea and ignore questions concern-ing the determination of this,its dependence on the size of the reference object, etcetera.See Crangle and Suppes(1989)for discussion.Also the differences be-tween on and at(like on the desk vs.at the desk)are ignored.We refer to the literature mentioned earlier.

9.Recall a partial order on is a relation that satis?es for all:

(re?exivity),if and then(antisymmetry),if and then(transitivity).

10.Whether beside should really be upward monotone as our de?nition implies is not completely clear.It may be that in English this preposition carries an element of proximity,which would put it in the other category.

11.Given the special type of this preposition,its monotonicity is determined by a trivial variation on de?nition7.

17

12.A measure phrase like less than0m is trivial as it denotes a constant function returning the empty set.

13.Recall a determiner is conservative iff for all and.

14.(28)is suf?cient,but not necessary,for conservativity to hold.See below. References

Barwise,J.and Cooper,R.(1981).Generalized quanti?ers and natural language.

Linguistics and Philosophy,4:159–219.

Crangle,C.and Suppes,P.(1989).Geometrical semantics for spatial prepositions.

Midwest Studies in Philosophy,14:399–422.

Herskovits,A.(1986).Language and Spatial Cognition:an interdisciplinary study of the prepositions in English.Cambridge University Press,Cambridge. Keenan,E.(1996).The semantics of determiners.In Lappin,S.,editor,The Hand-book of Contemporary Semantic Theory.Blackwell.

Kelley,J.L.(1961).General Topology.Van Nostrand,Princeton,New Jersey. Lang,S.(1977).Linear Algebra.Addison-Wesley,Reading,Massachusetts,second edition.

Thijsse,E.(1983).On some proposed universals of natural language.In ter Meulen,

A.,editor,Studies in Modeltheoretic Semantics.Foris,Dordrecht.

van Benthem,J.(1984).Questions about quanti?ers.Journal of Symbolic Logic, 49:443–466.

Vandeloise,C.(1991).Spatial Prepositions.Chicago University Press,Chicago. Wall,C.T.C.(1972).A Geometric Introduction to Topology.Addison-Wesley, Reading,Massachusetts.

Wunderlich,D.(1991).How do prepositional phrases?t into compositional syntax and semantics.Linguistics,29:591–621.

Zwarts,J.(1995).The semantics of relative position.In Proceedings of Semantics and Linguistic Theory,SALT5.A revised version is to appear in Journal of Semantics.

Zwarts:Joliotplaats666,3069TS Rotterdam,The Netherlands.

Winter:U.i.L.OTS,Trans10,3512JK Utrecht,The Netherlands.

E-mail:yoad.winter@let.ruu.nl

WWW:http://wwwots.let.ruu.nl/cgi-bin/staff?winter

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Unit1 Americans believe no one stands still. If you are not moving ahead, you are falling behind. This attitude results in a nation of people committed to researching, experimenting and exploring. Time is one of the two elements that Americans save carefully, the other being labor. "We are slaves to nothing but the clock,” it has been said. Time is treated as if it were something almost real. We budget it, save it, waste it, steal it, kill it, cut it, account for it; we also charge for it. It is a precious resource. Many people have a rather acute sense of the shortness of each lifetime. Once the sands have run out of a person’s hourglass, they cannot be replaced. We want every minute to count. A foreigner’s first impression of the U.S. is li kely to be that everyone is in a rush -- often under pressure. City people always appear to be hurrying to get where they are going, restlessly seeking attention in a store, or elbowing others as they try to complete their shopping. Racing through daytime meals is part of the pace

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天，成为信息检索的一个难题，本文中对本体层概念的推理就是为了探索计算机理解语义所做的一个尝试。语义网的体系结构向我们说明了语义网中各个层次的功能和特征，语义网的研究是阶段性的，首先解决syntax(语法)层面的问题，也就是xml，然后是解决(数据层)基本资源描述问题，也就是rdf,然后是(本体层)对资源间关系的形式化描述，就是owl，damloil，这三步已经基本告罄，当然，基于rdf 或者owl的数据挖掘和ontology管理(如合并，映射，进化)按TIMBERNERS-LEE的构想，这个工作大概到2008左右可以完成，在商业上，很快就会在知识管理，数据挖掘，数据集成方面出现一些企业。目前亟待发展的是LogicLayer(逻辑层)，这方面在国内外的期刊著作中还少有提到，接下来的工作就应该是对于owlbased的数据进行推理和查询了，当前的推理方法主要是针对本体而言的，而本体的概念是在某个特定领域范围内的，而且在知识库中推理和查询是紧密的结合在一起的，相辅相成的，查询的同时必然存在着推理，而这里的推理就必须要建立在一定的逻辑模型的基础上，所以推理的方法就是基于逻辑模型的逻辑推理，可采用逻辑推理的方法。本体中推理的重点在于推理结论的正确性、完备性，若是不能保证推理的正确性，则语义网的引入就不但没有给网络资源的查询带来便利，反而阻碍了网络的发展，而且还要保证推理的完备，不遗漏应有的推理结果。本体推理的难点在于推理的高效性、资源利用率，若推理虽能达到正确性，完备性的目的而浪费了大量的时间和资源，则语义网也不能达到预期的效果，所以推理方法的使用及其效果是语义网成功的关

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语义网本体

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