Public announcement logic is an extension of multi-agent epistemic logic with dynamic operators t... more Public announcement logic is an extension of multi-agent epistemic logic with dynamic operators to model the informational consequences of announcements to the entire group of agents. We propose an extension of public announcement logic with a dynamic modal operator that expresses what is true after any announcement: ♦ϕ expresses that there is a truthful announcement ψ after which ϕ is true. This logic gives a perspective on Fitch's knowability issues: for which formulas ϕ does it hold that ϕ → ♦Kϕ? We give various semantic results, and we show completeness for a Hilbert-style axiomatization of this logic. There is a natural generalization to a logic for arbitrary events. *
... The agent's goal is to marry the princess and to stay alive. Notice that lis... more ... The agent's goal is to marry the princess and to stay alive. Notice that listen(i) is an epistemic action and open(i) is an ontic action. ... The first one contains no modal operators. These formu-lae are called boolean formulae and we note this fragment LPL. ...
This paper presents a success case of using free software platforms for research and free softwar... more This paper presents a success case of using free software platforms for research and free software/model development for Earth System studies. We describe the technologies and methodologies used for this purpose. We also discuss the main results, challenges and solutions found on constructing a sustainable free software project which should serve as a foundation for the development of state-of-the-art environmental
Many modeling and simulation platforms provide general programming languages as interfaces for mo... more Many modeling and simulation platforms provide general programming languages as interfaces for model construction. Some offers highlevel modeling languages with conceptual basis and services to represent data structures and rules that will determine the model behavior. However, the direct use of a computational language is still a limiting factor to the broad usage of these platforms. Modelers often have different scientific backgrounds, presenting a lack of background on algorithms and programming techniques. Furthermore, there is no established methodology for model development. These problems confuse the modelers forcing them to deviate their attention from the problem being solved. We argue that a visual integrated development environment (IDE) can solve these problems, making easy the understanding and communication of the model conception and design. An IDE can also enforce the use of a common model development methodology. In this paper we describe a methodology for modeling Earth system phenomena using the TerraME GIMS tool, which is a visual IDE for the TerraME modeling and simulation platform. It enables users to build environmental models through visual metaphors that graphically describe models structure. We demonstrate the use of TerraME GIMS and present our methodology for the development of a didactic model for the hydrologic cycle. Future works include the development of diagrams to better describe the model behavior, including agent synchronization and communication.
2013 3rd International Workshop on Developing Tools as Plug-Ins (TOPI), 2013
TerraME is a platform for modeling and simulation of environmental systems that offers a conceptu... more TerraME is a platform for modeling and simulation of environmental systems that offers a conceptual basis and services to build environmental models through a high-level programming language called Terra Modeling Language. However, the use of a programming language is still a limiting factor since its main users are researchers with different backgrounds who usually lack basic knowledge of algorithms and programming techniques. So, this work presents the development of TerraME GIMS, an Eclipse plug-in for environmental systems modeling through visual metaphors that graphically represent the model.
One way to allocate tasks to agents is by ascribing them obligations. From obligations to be, age... more One way to allocate tasks to agents is by ascribing them obligations. From obligations to be, agents are able to infer what are the forbidden, permitted and obligatory actions they may perform, by using the wellknown Meyer's reduction from obligations to be to obligations to do. However, we show through an example that this method is not completely adequate to guide agents' decisions. We then propose a solution using, instead of obligations, the concept of 'responsibility'. To formalise responsibility we use a multi-agent extension of propositional dynamic logic as framework, and then we define some basic concepts, such as 'agent ability', also briefly discussing the problem of uniform strategies and a possible solution. In the last part, we show that our framework can be used in the specification of normative multi-agent systems, by presenting an extensive running example.
It has been proposed that a good way of allocating tasks to agents is by ascribing them obligatio... more It has been proposed that a good way of allocating tasks to agents is by ascribing them obligations, i.e., if we want agent i achieves ϕ, we can stipulate that 'it is obligatory for i that ϕ'. Here, we argue that this method is not adequate to guide agent's decisions. Then, using a multi-agent extension of propositional dynamic logic, with operators expressing agents' knowledge and abilities, we show that when agents' decisions are guided by responsibilities, as we define here, a successful performance is more likely to be obtained.
Abstract. We propose a formal semantics of intention and plan dy-namics based on the notion of lo... more Abstract. We propose a formal semantics of intention and plan dy-namics based on the notion of local assignment. The function of a local assignment is to change the truth value of a given proposition at a specific time point along a history. We combine a static modal logic ...
KNAW Narcis. Back to search results. Publication Optimal regression for reasoning about knowledge... more KNAW Narcis. Back to search results. Publication Optimal regression for reasoning about knowledge and actions (2007) Open access. Pagina-navigatie: Main. Title, Optimal regression for reasoning about knowledge and actions. ...
We present a logical approach to intention change. Inspired by Bratman’s theory, we define intent... more We present a logical approach to intention change. Inspired by Bratman’s theory, we define intention as the choice to perform a given action at a certain time point in the future. This notion is modeled in a modal logic containing a temporal modality and modal operators for belief and choice. Intention change is then modeled by a specific kind of dynamic operator, that we call ‘local assignment’. This is an operation on the model that changes the truth value of atomic formulae at specific time points. Two particular kinds of intention change are considered in some detail: intention generation and intention reconsideration.
Public announcement logic is an extension of multi-agent epistemic logic with dynamic operators t... more Public announcement logic is an extension of multi-agent epistemic logic with dynamic operators to model the informational consequences of announcements to the entire group of agents. We propose a labelled tableau-calculus for this logic. We also present an extension of the calculus for a logic of arbitrary announcements.
Abstract. We continue the work initiated in [1,2,3], where the accep-tance logic, a modal logic f... more Abstract. We continue the work initiated in [1,2,3], where the accep-tance logic, a modal logic for modelling individual and collective accep-tances was introduced. This logic is aimed at capturing the concept of acceptance qua member of an institution as the kind of attitude that agents ...
Public announcement logic is an extension of multi-agent epistemic logic with dynamic operators t... more Public announcement logic is an extension of multi-agent epistemic logic with dynamic operators to model the informational con- sequences of announcements to the entire group of agents. We propose an extension of public announcement logic with a dynamic modal operator that expresses what is true after arbitrary announcements. Intuitively, (!)' expresses that ' is true after an arbitrary announcement . We show com- pleteness for a Hilbert-style axiomatization of this logic, and also provide a labelled tableau-calculus.
In this paper we investigate a logic for modelling individual and collective acceptances that is ... more In this paper we investigate a logic for modelling individual and collective acceptances that is called acceptance logic. The logic has formulae of the form A G
Theoretical Aspects of Rationality and Knowledge, 2007
Public announcement logic is an extension of multi-agent epistemic logic with dynamic operators t... more Public announcement logic is an extension of multi-agent epistemic logic with dynamic operators to model the informational conse- quences of announcements to the entire group of agents. We propose an extension of public announcement logic with a dynamic modal operator that expresses what is true after any announcement: ' expresses that ' is true after an arbitrary announcement . As
Public announcement logic is an extension of multi-agent epistemic logic with dynamic operators t... more Public announcement logic is an extension of multi-agent epistemic logic with dynamic operators to model the informational consequences of announcements to the entire group of agents. We propose an extension of public announcement logic with a dynamic modal operator that expresses what is true after any announcement: ♦ϕ expresses that there is a truthful announcement ψ after which ϕ is true. This logic gives a perspective on Fitch's knowability issues: for which formulas ϕ does it hold that ϕ → ♦Kϕ? We give various semantic results, and we show completeness for a Hilbert-style axiomatization of this logic. There is a natural generalization to a logic for arbitrary events. *
... The agent's goal is to marry the princess and to stay alive. Notice that lis... more ... The agent's goal is to marry the princess and to stay alive. Notice that listen(i) is an epistemic action and open(i) is an ontic action. ... The first one contains no modal operators. These formu-lae are called boolean formulae and we note this fragment LPL. ...
This paper presents a success case of using free software platforms for research and free softwar... more This paper presents a success case of using free software platforms for research and free software/model development for Earth System studies. We describe the technologies and methodologies used for this purpose. We also discuss the main results, challenges and solutions found on constructing a sustainable free software project which should serve as a foundation for the development of state-of-the-art environmental
Many modeling and simulation platforms provide general programming languages as interfaces for mo... more Many modeling and simulation platforms provide general programming languages as interfaces for model construction. Some offers highlevel modeling languages with conceptual basis and services to represent data structures and rules that will determine the model behavior. However, the direct use of a computational language is still a limiting factor to the broad usage of these platforms. Modelers often have different scientific backgrounds, presenting a lack of background on algorithms and programming techniques. Furthermore, there is no established methodology for model development. These problems confuse the modelers forcing them to deviate their attention from the problem being solved. We argue that a visual integrated development environment (IDE) can solve these problems, making easy the understanding and communication of the model conception and design. An IDE can also enforce the use of a common model development methodology. In this paper we describe a methodology for modeling Earth system phenomena using the TerraME GIMS tool, which is a visual IDE for the TerraME modeling and simulation platform. It enables users to build environmental models through visual metaphors that graphically describe models structure. We demonstrate the use of TerraME GIMS and present our methodology for the development of a didactic model for the hydrologic cycle. Future works include the development of diagrams to better describe the model behavior, including agent synchronization and communication.
2013 3rd International Workshop on Developing Tools as Plug-Ins (TOPI), 2013
TerraME is a platform for modeling and simulation of environmental systems that offers a conceptu... more TerraME is a platform for modeling and simulation of environmental systems that offers a conceptual basis and services to build environmental models through a high-level programming language called Terra Modeling Language. However, the use of a programming language is still a limiting factor since its main users are researchers with different backgrounds who usually lack basic knowledge of algorithms and programming techniques. So, this work presents the development of TerraME GIMS, an Eclipse plug-in for environmental systems modeling through visual metaphors that graphically represent the model.
One way to allocate tasks to agents is by ascribing them obligations. From obligations to be, age... more One way to allocate tasks to agents is by ascribing them obligations. From obligations to be, agents are able to infer what are the forbidden, permitted and obligatory actions they may perform, by using the wellknown Meyer's reduction from obligations to be to obligations to do. However, we show through an example that this method is not completely adequate to guide agents' decisions. We then propose a solution using, instead of obligations, the concept of 'responsibility'. To formalise responsibility we use a multi-agent extension of propositional dynamic logic as framework, and then we define some basic concepts, such as 'agent ability', also briefly discussing the problem of uniform strategies and a possible solution. In the last part, we show that our framework can be used in the specification of normative multi-agent systems, by presenting an extensive running example.
It has been proposed that a good way of allocating tasks to agents is by ascribing them obligatio... more It has been proposed that a good way of allocating tasks to agents is by ascribing them obligations, i.e., if we want agent i achieves ϕ, we can stipulate that 'it is obligatory for i that ϕ'. Here, we argue that this method is not adequate to guide agent's decisions. Then, using a multi-agent extension of propositional dynamic logic, with operators expressing agents' knowledge and abilities, we show that when agents' decisions are guided by responsibilities, as we define here, a successful performance is more likely to be obtained.
Abstract. We propose a formal semantics of intention and plan dy-namics based on the notion of lo... more Abstract. We propose a formal semantics of intention and plan dy-namics based on the notion of local assignment. The function of a local assignment is to change the truth value of a given proposition at a specific time point along a history. We combine a static modal logic ...
KNAW Narcis. Back to search results. Publication Optimal regression for reasoning about knowledge... more KNAW Narcis. Back to search results. Publication Optimal regression for reasoning about knowledge and actions (2007) Open access. Pagina-navigatie: Main. Title, Optimal regression for reasoning about knowledge and actions. ...
We present a logical approach to intention change. Inspired by Bratman’s theory, we define intent... more We present a logical approach to intention change. Inspired by Bratman’s theory, we define intention as the choice to perform a given action at a certain time point in the future. This notion is modeled in a modal logic containing a temporal modality and modal operators for belief and choice. Intention change is then modeled by a specific kind of dynamic operator, that we call ‘local assignment’. This is an operation on the model that changes the truth value of atomic formulae at specific time points. Two particular kinds of intention change are considered in some detail: intention generation and intention reconsideration.
Public announcement logic is an extension of multi-agent epistemic logic with dynamic operators t... more Public announcement logic is an extension of multi-agent epistemic logic with dynamic operators to model the informational consequences of announcements to the entire group of agents. We propose a labelled tableau-calculus for this logic. We also present an extension of the calculus for a logic of arbitrary announcements.
Abstract. We continue the work initiated in [1,2,3], where the accep-tance logic, a modal logic f... more Abstract. We continue the work initiated in [1,2,3], where the accep-tance logic, a modal logic for modelling individual and collective accep-tances was introduced. This logic is aimed at capturing the concept of acceptance qua member of an institution as the kind of attitude that agents ...
Public announcement logic is an extension of multi-agent epistemic logic with dynamic operators t... more Public announcement logic is an extension of multi-agent epistemic logic with dynamic operators to model the informational con- sequences of announcements to the entire group of agents. We propose an extension of public announcement logic with a dynamic modal operator that expresses what is true after arbitrary announcements. Intuitively, (!)' expresses that ' is true after an arbitrary announcement . We show com- pleteness for a Hilbert-style axiomatization of this logic, and also provide a labelled tableau-calculus.
In this paper we investigate a logic for modelling individual and collective acceptances that is ... more In this paper we investigate a logic for modelling individual and collective acceptances that is called acceptance logic. The logic has formulae of the form A G
Theoretical Aspects of Rationality and Knowledge, 2007
Public announcement logic is an extension of multi-agent epistemic logic with dynamic operators t... more Public announcement logic is an extension of multi-agent epistemic logic with dynamic operators to model the informational conse- quences of announcements to the entire group of agents. We propose an extension of public announcement logic with a dynamic modal operator that expresses what is true after any announcement: ' expresses that ' is true after an arbitrary announcement . As
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