- then, define the atomic qualitative relations that are susceptible to be applied to
these spatial entities. These relations are mainly of directional or topological order.
Other relations can appear, such as those dealing with the size of objects, the distance
separating them or simply their shape.
Figure 2.2. The eight topological relations existing between two x and y
regions according to the RCC-8 [RAN 92] model - illustration
taken from [LES 07]
The pieces of work described in [FRE 92], [DEN 97], [LIG 98], [TAL 00] and
[LEB 07] are also referential in the field of spatial reasoning.
Parallel to these pieces of work, from a linguistic point of view, Vandeloise
[VAN 86] and Borillo [BOR 98] show the particular way humans describe spatial
information when it comes to writing: referring to a place involves several elements
and these elements' positions within the sentence comply with some rules. They
propose the concept of target/site: in written language, the target corresponds to the
subject of the description and the site constitutes the element of reference. For
instance, in the sentence “The car is close to the tree”, the car is the target and the
tree is the site. This concept is often used in travelogues. The target is defined here by
one or more sites associated with topological, adjacency, orientation or distance
indicators or a combination of these. For instance, the text “Beyond Pau, the
landscape becomes dull, [...] I have walked from Assat to Eaux-Chaudes...”, taken
from the topic Voyages aux Pyrénées - Pimientos editions, describes two places: (1)
the surroundings of Pau whose place of reference is Pau and (2) the zone between
Assat and Eaux-Chaudes whose two places of reference are Assat and
Eaux-Chaudes. The indicators used here are the indicators of adjacency.