Questions and Answers on
Dynamic Activities of Agents
Marie Duží
VSB-Technical University of Ostrava,
Department of Computer Science FEI,
17. listopadu 15, 708 33 Ostrava, Czech Republic
Abstract. In a multiagent and multi-cultural world, the fine-grained anal-
ysis of agents’ dynamic behaviour, i.e. of their activities, is essential. Dy-
namic activities are actions that are characterised by an agent who executes
the action and by other participants of the action. Wh-questions on the
participants of the actions pose a difficult particular challenge because the
variability of the types of possible answers to such questions is huge. To
deal with the problem, we proposed the classification of the participants of
activities that is inspired by linguistic classification of verb valency verbs.
The application of these results to the analysis of processes and events and
to questioning and answering about these activities is a novelty of the pa-
per.
Keywords: Activity · Communication of agents · Transparent Intensional
Logic · Wh-questions and answers
1 Introduction
The primary goal of this paper is to logically analyse processes and activities
so that the agents in a multiagent and multicultural world can ask on the
participants of such activities. To this end, we have defined different kinds of
possible participants of an activity; this classification is inspired by linguistic
verb valency frames. Hence, different kinds of Wh-questions and plausible
answers can be derived, as each specialised subtype of a Wh-question conveys
specific information for an agent on how and where to seek the corresponding
direct answer. In addition, by applying TIL deduction system, the agents can
infer even more detailed answers, if needed. Thus, we wish to provide not
only direct answers extracted from natural-language texts or agents’ knowledge
bases just by keywords; rather, we also want to derive logical consequences of
such answers. Currently, the need of a hyperintensional approach to natural-
language processing is broadly recognised. For these reasons, we vote for
Transparent Intensional Logic (TIL) as our background theory.1 Duží and Fait
introduce in [7] Genzen’s system of natural deduction adjusted for TIL and
1
See, for instance, [5], [15], [14], [8].
A. Horák, P. Rychlý, A. Rambousek (eds.): Proceedings of Recent Advances in Slavonic Natural Language
Processing, RASLAN 2021, pp. 71–81, 2021. © Tribun EU 2021
, 72 M. Duží
natural-language processing. The analysis of Wh-questions results into 𝜆-terms
with a free variable 𝑥 ranging over entities of type 𝛼, which is the type of a
possible direct answer. The system provides answers by suitable substitutions
of the 𝛼-entities extracted from input sentences, the constituents of which match
a given 𝜆-term. It also makes it possible to derive as an answer even more
information by applying the semantic rules rooted in the rich semantics of a
natural language. In particular, the agents can make use of the relations of
requisites and pre-requisites between intensions.
The rest of the paper is organised as follows. Section 2 introduces the basic
principles of Transparent Intensional Logic (TIL) that is my background logical
system. Section 3 introduces the main results of this paper; it deals with the
TIL technique of answering Wh-questions, and concentrates in particular on the
dynamic activities of agents. Concluding remarks can be found in Section 4.
2 Basic principles of TIL
Pavel Tichý, the founder of Transparent Intensional Logic (TIL) was inspired by
Frege’s semantic triangle.2 However, while Frege did not define the sense of an
expression but only characterised it as the ‘mode of presentation’, Tichý ([21],
[22]) defined the sense of an expression, i.e. its meaning, as an abstract, algorith-
mically structured procedure that produces the object denoted by the expression,
or in rigorously defined cases fails to produce a denotation if there is none.3
Tichý in [25] defined six kinds of meaning procedures and called them
constructions. There are two kinds of atomic constructions that present input
objects to be operated on by molecular constructions. They are Trivialization
and variables. Trivialisation of an object 𝑋 presents the object 𝑋 without the
mediation of any other procedures. Using the terminology of programming
languages, the Trivialisation of 𝑋, denoted by ‘0𝑋’, is just a pointer or reference
to 𝑋. Trivialization can present an object of any type, even another construction
𝐶. Hence, if 𝐶 is a construction, 0𝐶 is said to present the construction 𝐶, whereby
𝐶 occurs hyperintensionally, i.e. in the non-executed mode. Variables produce
objects dependently on valuations; they are said to v-construct. The execution of
a Trivialisation or a variable never fails to produce an object. However, since TIL
is a logic of partial functions, the execution of some of the molecular constructions
can fail to present an object of the type they are typed to produce. When
this happens, we say that a given construction is v-improper. This concerns in
particular one of the molecular constructions, namely Composition, [𝑋𝑋1 … 𝑋𝑚 ].
It is the very procedure of applying a function f produced by 𝑋 (if any) to
the tuple argument ⟨𝑎1 … 𝑎𝑚 ⟩ (if any) produced by the procedures 𝑋1 , … , 𝑋𝑚 .
A Composition is 𝑣-improper as soon as 𝑓 is a partial function not defined
at its tuple argument, or if one or more of its constituents 𝑋, 𝑋1 , … , 𝑋𝑚 are
𝑣-improper. Another molecular construction is 𝜆-Closure, [𝜆𝑥1 … 𝑥𝑚 𝑋]. It is
2
See [25].
3
A similar philosophy of meaning as a ‘generalized algorithm’ can be found in [18];
this conception has been further developed by Loukanova, see [17].
Dynamic Activities of Agents
Marie Duží
VSB-Technical University of Ostrava,
Department of Computer Science FEI,
17. listopadu 15, 708 33 Ostrava, Czech Republic
Abstract. In a multiagent and multi-cultural world, the fine-grained anal-
ysis of agents’ dynamic behaviour, i.e. of their activities, is essential. Dy-
namic activities are actions that are characterised by an agent who executes
the action and by other participants of the action. Wh-questions on the
participants of the actions pose a difficult particular challenge because the
variability of the types of possible answers to such questions is huge. To
deal with the problem, we proposed the classification of the participants of
activities that is inspired by linguistic classification of verb valency verbs.
The application of these results to the analysis of processes and events and
to questioning and answering about these activities is a novelty of the pa-
per.
Keywords: Activity · Communication of agents · Transparent Intensional
Logic · Wh-questions and answers
1 Introduction
The primary goal of this paper is to logically analyse processes and activities
so that the agents in a multiagent and multicultural world can ask on the
participants of such activities. To this end, we have defined different kinds of
possible participants of an activity; this classification is inspired by linguistic
verb valency frames. Hence, different kinds of Wh-questions and plausible
answers can be derived, as each specialised subtype of a Wh-question conveys
specific information for an agent on how and where to seek the corresponding
direct answer. In addition, by applying TIL deduction system, the agents can
infer even more detailed answers, if needed. Thus, we wish to provide not
only direct answers extracted from natural-language texts or agents’ knowledge
bases just by keywords; rather, we also want to derive logical consequences of
such answers. Currently, the need of a hyperintensional approach to natural-
language processing is broadly recognised. For these reasons, we vote for
Transparent Intensional Logic (TIL) as our background theory.1 Duží and Fait
introduce in [7] Genzen’s system of natural deduction adjusted for TIL and
1
See, for instance, [5], [15], [14], [8].
A. Horák, P. Rychlý, A. Rambousek (eds.): Proceedings of Recent Advances in Slavonic Natural Language
Processing, RASLAN 2021, pp. 71–81, 2021. © Tribun EU 2021
, 72 M. Duží
natural-language processing. The analysis of Wh-questions results into 𝜆-terms
with a free variable 𝑥 ranging over entities of type 𝛼, which is the type of a
possible direct answer. The system provides answers by suitable substitutions
of the 𝛼-entities extracted from input sentences, the constituents of which match
a given 𝜆-term. It also makes it possible to derive as an answer even more
information by applying the semantic rules rooted in the rich semantics of a
natural language. In particular, the agents can make use of the relations of
requisites and pre-requisites between intensions.
The rest of the paper is organised as follows. Section 2 introduces the basic
principles of Transparent Intensional Logic (TIL) that is my background logical
system. Section 3 introduces the main results of this paper; it deals with the
TIL technique of answering Wh-questions, and concentrates in particular on the
dynamic activities of agents. Concluding remarks can be found in Section 4.
2 Basic principles of TIL
Pavel Tichý, the founder of Transparent Intensional Logic (TIL) was inspired by
Frege’s semantic triangle.2 However, while Frege did not define the sense of an
expression but only characterised it as the ‘mode of presentation’, Tichý ([21],
[22]) defined the sense of an expression, i.e. its meaning, as an abstract, algorith-
mically structured procedure that produces the object denoted by the expression,
or in rigorously defined cases fails to produce a denotation if there is none.3
Tichý in [25] defined six kinds of meaning procedures and called them
constructions. There are two kinds of atomic constructions that present input
objects to be operated on by molecular constructions. They are Trivialization
and variables. Trivialisation of an object 𝑋 presents the object 𝑋 without the
mediation of any other procedures. Using the terminology of programming
languages, the Trivialisation of 𝑋, denoted by ‘0𝑋’, is just a pointer or reference
to 𝑋. Trivialization can present an object of any type, even another construction
𝐶. Hence, if 𝐶 is a construction, 0𝐶 is said to present the construction 𝐶, whereby
𝐶 occurs hyperintensionally, i.e. in the non-executed mode. Variables produce
objects dependently on valuations; they are said to v-construct. The execution of
a Trivialisation or a variable never fails to produce an object. However, since TIL
is a logic of partial functions, the execution of some of the molecular constructions
can fail to present an object of the type they are typed to produce. When
this happens, we say that a given construction is v-improper. This concerns in
particular one of the molecular constructions, namely Composition, [𝑋𝑋1 … 𝑋𝑚 ].
It is the very procedure of applying a function f produced by 𝑋 (if any) to
the tuple argument ⟨𝑎1 … 𝑎𝑚 ⟩ (if any) produced by the procedures 𝑋1 , … , 𝑋𝑚 .
A Composition is 𝑣-improper as soon as 𝑓 is a partial function not defined
at its tuple argument, or if one or more of its constituents 𝑋, 𝑋1 , … , 𝑋𝑚 are
𝑣-improper. Another molecular construction is 𝜆-Closure, [𝜆𝑥1 … 𝑥𝑚 𝑋]. It is
2
See [25].
3
A similar philosophy of meaning as a ‘generalized algorithm’ can be found in [18];
this conception has been further developed by Loukanova, see [17].
