Borning, A., Freeman-Benson, B., The OTI Constraint Solver: A Constraint Library for Constructing Interactive Graphical User Interfaces, in: Principles and Practice of Constraint Programming - CP95 (U.Montanari, F.Rossi eds.), pp. 624-628, Cassis, France, 1995.  Home/Search   Document Details and Download   Summary   Related Articles   Check

....has been studied by many authors [44, 2, 8, 10, 11, 28, 31, 38, 39, 43] following very different approaches which we divide in two main classes: numerical approaches and formal methods. The first ones, mainly used in CAD, consist in solving numerically the equation system related to the dimensions [23, 30, 31, 6, 14]. A formal resolution of the symbolic constraints system allows to efficiently manipulate the defined figure 15 20 18 13 12 Figure 1: 2 triangles configuration: the sketch Figure 2: Two solutions by varying parameters values [2, 10, 11, 17] It is well known that algebraic tools for formal ....

A. Borning and B. N. Freeman-Benson. The OTI Constraint Solver: A Constraint Library for Constructing Interactive Graphical User Interfaces. In Principles and Practice of Constraint Programming - CP'95, First International Conference, pages 624--628, 1995.

....based on constraints or on traditional techniques) may be useful in many CLP applications to help the user in the modeling phase. In the following we give examples of both kinds of systems. A commercial constraint library for constructing interactive graphical user interfaces is presented in [24]. The company Object Technology International has used this library to build a graphical editor for a large database. A recently developed object oriented constraint solving toolkit, called QOCA, provides a simple and flexible interface for interactive graphical applications [122] Such a system ....

A. Borning and B. N. Freeman-Benson. The OTI constraint solver: a constraint library for constructing graphical user interfaces. In Proceedings 1st Int. Conference on Principles and Practice of Constraint Programming (CP95). Springer-Verlag, LNCS 976, 1995.

....containing the same variables, e.g. the system of equations (x y=3, x y=1) Such a system of constraints corresponds to the cycle in the constraint graph, hence we speak about cycles of constraints. Some local propagation algorithms solve constraint cycles by evoking an external solver [7]. We mentioned the way a constraint is used to compute the value of one of its variables in the above paragraphs. The constraint is assumed there to be a total function that uniquely computes the value of the output variable from the values of input variables. However, this approach disables ....

Borning, A., Freeman-Benson, B., The OTI Constraint Solver: A Constraint Library for Constructing Interactive Graphical User Interfaces, in: Proceedings of the First International Conference on Principles and Practice of Constraint Programming, pp. 624-628, Cassis, France, September 1995

....of some of the motion parameters (location, velocity) at certain times (Cohen 1992) In these cases, constraints are used to generate a piece of motion, which is a more limited usage than in our case. Finally, the user interface of our animation editor brings into mind graphical user interfaces (Borning et al. 1995, 1996, 1998) layout systems (Oster et al. 1998, Vander Zanden et al. 1995, Pachet et al. 1998) and systems supporting musical composition (Pachet 1999) which apply constraints and often use some specific incremental propagation method to update solutions. What makes our animation editor ....

Borning, A., Freeman-Benson, B. (1995) The OTI constraint solver: a constraint library for constructing interactive graphical user interfaces, Proc. of the First International Conference on Principles and Practice of Constraint Programming , pp. 624-628.

....systems of constraints by specifying constraints with hierarchical strengths or preferences 2 . Constraint hierarchies are widely used in areas like HCLP (Hierarchical Constraint Logic Programming) 4, 21] CIP (Constraint Imperative Programming) 8] and graphical user interfaces construction [5]. The major advantage of constraint hierarchies is their declarative expression of preferences or strengths of constraints rather than encoding them in the procedural parts of the language. In a constraint hierarchy, the stronger a constraint is, the more it influences the solution of the ....

Borning, A., Freeman-Benson, B., The OTI Constraint Solver: A Constraint Library for Constructing Interactive Graphical User Interfaces, in: Proceedings of the First International Conference on Principles and Practice of Constraint Programming, pp. 624-628, Cassis, France, September 1995

.... [9, 25] an extension of CLP (Constraint Logic Programming) 15] to include constraint hierarchies, CIP (Constraint Imperative Programming) 16] an integration of declarative constraint programming and imperative object oriented programming, and graphical user interfaces construction [8]. The major advantage of constraint hierarchies is their declarative expression of preferences or strengths of constraints rather than encoding them in the procedural parts of the language. In a constraint hierarchy, the stronger a constraint is, the more it influences the solution of the ....

....containing the same variables, e.g. the system of equations (x y=3, x y=1) Such a system of constraints corresponds to the cycle in the constraint graph, hence we speak about cycles of constraints. Some local propagation algorithms solve constraint cycles by evoking an external solver [8]. We mentioned the way a constraint is used to compute the value of one of its variables in the above paragraphs. The constraint is assumed there to be a function that computes the value of the output variable from the values of input variables. However, this approach disables many types of ....

Borning, A., Freeman-Benson, B., The OTI Constraint Solver: A Constraint Library for Constructing Interactive Graphical User Interfaces, in: Proceedings of the First International Conference on Principles and Practice of Constraint Programming, pp. 624-628, Cassis, France, September 1995

.... [8, 23] an extension of CLP (Constraint Logic Programming) 13] to include constraint hierarchies, CIP (Constraint Imperative Programming) 14] an integration of declarative constraint programming and imperative object oriented programming, and graphical user interfaces construction [7]. The major advantage of constraint hierarchies is their declarative expression of preferences or strengths of constraints rather than encoding them in the procedural parts of the language. In a constraint hierarchy, the stronger a constraint is, the more it influences the solution of the ....

....containing the same variables, e.g. the system of equations (x y=3, x y=1) Such a system of constraints corresponds to the cycle in the constraint graph, hence we speak about cycles of constraints. Some local propagation algorithms solve constraint cycles by evoking an external solver [7]. We mentioned the way a constraint is used to compute the value of one of its variables in the above paragraphs. The constraint is assumed there to be a function that computes the value of the output variable from the values of input variables. However, this approach disables many types of ....

Borning, A., Freeman-Benson, B., The OTI Constraint Solver: A Constraint Library for Constructing Interactive Graphical User Interfaces, in: Proceedings of the First International Conference on Principles and Practice of Constraint Programming, pp. 624-628, Cassis, France, September 1995

....of some of the motion parameters (location, velocity) at certain times (Cohen 1992) In these cases, constraints are used to generate a piece of motion, which is a more limited usage than in our case. Finally, the user interface of our animation editor brings into mind graphical user interfaces (Borning et al. 1995, 1996, 1998) layout systems (Oster et al. 1998, Vander Zanden et al. 1995, Pachet et al. 1998) and systems supporting musical composition (Pachet 1999) which apply constraints and often use some specific incremental propagation method to update solutions. What makes our animation editor ....

Borning, A., Freeman-Benson, B. (1995) The OTI constraint solver: a constraint library for constructing interactive graphical user interfaces, Proc. of the First International Conference on Principles and Practice of Constraint Programming , pp. 624-628.

.... include QOCA [58] which solves simultaneous linear equation and inequality constraints while optimizing a quadratic expression, Bramble [46] and Juno 2 [65] which use numerical solvers, Indigo [9] an interval propagation algorithm for inequality constraints, and DETAIL [67] and Ultraviolet [10], both of which are hybrid algorithms supporting both local propagation and cycle solvers. 3.4 Constraint Programming in Operations Research Operations Research is a vast field represented by departments in major universities and industrial settings around the world. The field of OR has ....

A. Borning and B. Freeman-Benson. The OTI constraint solver: A constraint library for constructing interactive graphical user interfaces. In U. Montanari and F. Rossi, editors, Proceedings of the International Conference on Principles and Practice of Constraint Programming, volume 976, pages 624--628, Cassis, France, 1995. Springer-Verlag.

....such a case, it needs to perform special treatment of a cycle, which is considered to degenerate its performance. In addition to the demand for addressing such problems, we are now encountering a new trend that constraint hierarchy algorithms are differentiated into two levels: meta algorithms [10] and specialized algorithms [5] A meta algorithm maintains the whole constraint hierarchy. Intuitively, it divides the hierarchy into a set of sub hierarchies based on its graph topology, making appropriate specialized algorithms actually solve the subhierarchies. Since developing an efficient, ....

....limit constraint hierarchies to being statically defined, that is, they cannot dynamically change hierarchies after compilation. UltraViolet is a hybrid algorithm that divides constraint hierarchies into subgraphs based on graph topology and constraint types and then invokes appropriate subsolvers [8, 10]. Menezes s incremental hierarchical constraint solver satisfies constraint hierarchies over finite domains using a search technique [60] 7.5 Other Over Constrained Systems Hattori proposed executable constraints [31] Each executable constraint is a macro defined by an end user of a GUI system, ....

Borning, A. and B. N. Freeman-Benson, "The OTI Constraint Solver: A Constraint Library for Constructing Interactive Graphical User Interfaces, " in Principles and Practice of Constraint Programming---CP'95, vol. 976 of Lecture Notes in Computer Science, Springer-Verlag, Oct. 1995, pp. 624--628.

....such as maintaining consistency between the underlying data and a graphical depiction of that data, maintaining consistency among multiple views, and specifying formatting requirements. A commercial constraint library for constructing interactive graphical user interfaces is presented in [9]. Object Technology International has used the library to build a graphical editor for a large database. technology for graphical editors. Most modern tools, be they database browsers, calendar managers or systems for producing overhead projector presentations, have some sort of graphical editor. ....

A. Borning and B.N. Freeman-Benson. The OTI constraint solver: A constraint library for constructing graphical user interfaces. In Proc Principles and Practice of Constraint programming CP'95. Springer Verlag, 1995.

.... (beyond simply changing the constants in the v = b constraints) Some previous work has involved hybrid constraint solving algorithms, which partition a set of constraints into regions that can then be turned over to an appropriate sub solver for that class of constraint and constraint topology [3]. Compilation based on Fourier elimination is a promising candidate for use in this architecture, to handle cyclic collections of linear equality and inequality constraints. Theorem 4 is particularly interesting, because it shows how the structure of the constraints to be solved can be exploited ....

Alan Borning and Bjorn Freeman-Benson. The OTI constraint solver: A constraint library for constructing interactive graphical user interfaces. In Proceedings of the First International Conference on Principles and Practice of Constraint Programming, pages 624-628, Cassis, France, September 1995.

....that can be executed repeatedly to re solve the constraints with different input parameters. We can view this as a kind of partial evaluation of the constraint solving algorithm. This has long been done for local propagation solvers (e.g. 1] and more recently for simultaneous linear equations [3] and for acyclic sets of inequality constraints [2] However, there have not been any systems that can compile plans for systems of constraints including a cyclic set of simultaneous equalities and inequalities. That lack is addressed here. The original motivation for this work was constraint ....

.... (beyond simply changing the constants in the v = b constraints) Some previous work has involved hybrid constraint solving algorithms, which partition a set of constraints into regions that can then be turned over to an appropriate sub solver for that class of constraint and constraint topology [3]. Compilation based on Fourier elimination is a promising candidate for use in this architecture, to handle cyclic collections of linear equality and inequality constraints. Theorem 4 is particularly interesting, because it shows how the structure of the constraints to be solved can be exploited ....

Alan Borning and Bjorn Freeman-Benson. The OTI constraint solver: A constraint library for constructing interactive graphical user interfaces. In Proceedings of the First International Conference on Principles and Practice of Constraint Programming, pages 624-628, Cassis, France, September 1995.

.... et al. 1993; Vander Zanden 1996] Indigo [Borning et al. 1996] handles acyclic collections of inequality constraints, but not cycles (simultaneous equations and inequalities) User interface systems that handle simultaneous linear equations include DETAIL [Hosobe et al. 1996] and Ultraviolet [Borning and Freeman Benson 1995]. A number of researchers (including the second author) have experimented with a straightforward use of a simplex package in a UI constraint solver, but the speed was not satisfactory for interactive use. Bara# [Bara# 1994] describes a quadratic optimization algorithm for solving linear ....

Borning, A. and Freeman-Benson, B. 1995. The OTI constraint solver: A constraint library for constructing interactive graphical user interfaces. In Proceedings of the First International Conference on Principles and Practice of Constraint Programming (Cassis, France, Sept. 1995), pp. 624--628.

....for inequality constraints and cycles often use numeric algorithms. Notable examples are Juno [28] Juno 2 [18] and Briar and Bramble, which use a differential solver [12, 13, 14] An earlier version of Ultraviolet which doesn t include support for inequality constraints is described in [3]. 3. Constraint Hierarchy Solutions As described in the introduction, constraint hierarchies allow both required and preferential constraints. A solution to a constraint hierarchy is a mapping from variables to domain elements. Given a constraint hierarchy, if not all of the preferential ....

Alan Borning and Bjorn Freeman-Benson. The OTI constraint solver: A constraint library for constructing interactive graphical user interfaces. In Proceedings of the First International Conference on Principles and Practice of Constraint Programming, pages 624--628, Cassis, France, September 1995.

....and other numeric constraints; and two cycle solvers: Purple for cycles of linear equality constraints and Deep Purple for linear inequality constraints. The subsolvers communicate via shared variables. An earlier version of Ultraviolet which doesn t include Indigo is described in [Borning Freeman Benson 95] Ultraviolet has been implemented and tested, and Indigo has been tested separately as well as a standalone solver. The current version of Ultraviolet has also been used as the constraint solver in the Constraint Drawing Framework, a commercial graphics library written in Smalltalk. The ....

Alan Borning and Bjorn Freeman-Benson. The OTI constraint solver: A constraint library for constructing interactive graphical user interfaces. In Proceedings of the First International Conference on Principles and Practice of Constraint Programming, pages 624--628, Cassis, France, September 1995.

....and other numeric constraints; and two cycle solvers, one for cycles of linear equality constraints and one for linear inequality constraints. An earlier version of Ultraviolet that supports only functional constraints, including cycles with linear equations, is already in commercial use [3]; the new version, which also supports inequalities, has been designed and will be implemented over the next several months. However, Indigo is quite useful in its own right, so we present it here. CONSTRAINT HIERARCHY SOLUTIONS A solution to a constraint hierarchy is a mapping from variables ....

....bounds, substantially simplifies both the presentation and implementation of the algorithm. Finally we define the tighten message to variables (with an interval argument) to tighten the bounds on the variable if possible, given the argument. For example, if a variable currently has the bounds [3,10], if we tighten it using [5,8] its new bounds will be [5,8] On the other hand, if a variable current has the bounds [3,10] and we tighten it using [50,100] its new bounds will be the singleton interval [10,10] since 10 is the number within the interval [3,10] that minimizes the distance to the ....

[Article contains additional citation context not shown here]

Alan Borning and Bjorn Freeman-Benson. The OTI constraint solver: A constraint library for constructing interactive graphical user interfaces. In Proceedings of the First International Conference on Principles and Practice of Constraint Programming, pages 624--628, Cassis, France, September 1995.

.... solution is also a locally error better solution [4] It is thus easier to implement algorithms to find a locally error better solution, and in particular to design hybrid algorithms that include subsolvers for simultaneous equations and inequalities and also subsolvers for nonnumeric constraints [3]. Since each of these different comparators is preferable in certain situations we give algorithms for each. 1.2 Adapting the Simplex Algorithm Linear programming is concerned with solving the following problem. Consider a collection of n realvalued variables x 1 ; xn , each of which is ....

.... algorithms for acyclic collections of multi way constraints (e.g. 18, 20] Indigo [2] handles acyclic collections of inequality constraints, but not cycles (simultaneous equations and inequalities) UI systems that handle simultaneous linear equations include DETAIL [11] and Ultraviolet [3]. A number of researchers (including the first author) have experimented with a straightforward use of a simplex package in a UI constraint solver, but the speed was not satisfactory for interactive use. An earlier version of QOCA is described in references [9] and [10] These earlier ....

Alan Borning and Bjorn Freeman-Benson. The OTI constraint solver: A constraint library for constructing interactive graphical user interfaces. In Proceedings of the First International Conference on Principles and Practice of Constraint Programming, pages 624--628, Cassis, France, September 1995.

....and other numeric constraints; and two cycle solvers: Purple for cycles of linear equality constraints and Deep Purple for linear inequality constraints. The subsolvers communicate via shared variables. An earlier version of Ultraviolet which doesn t include Indigo is described in [5]. Ultraviolet has been implemented and tested, and Indigo has been tested separately as well as a standalone solver. The current version of Ultraviolet has also been used as the constraint solver in the Constraint Drawing Framework, a commercial graphics library written in Smalltalk. The ....

....both the presentation and implementation of the algorithm. Finally we define the tighten message to variables (with an interval argument) to tighten the bounds on the variable if possible, given the argument. For example, if a variable currently has the bounds [3,10] if we tighten it using [5,8], its new bounds will be [5,8] On the other hand, if a variable current has the bounds [3,10] and we tighten it using [50,100] its new bounds will be the singleton interval [10,10] since 10 is the number within the interval [3,10] that minimizes the distance to the interval [50,100] The ....

[Article contains additional citation context not shown here]

Alan Borning and Bjorn Freeman-Benson. The OTI constraint solver: A constraint library for constructing interactive graphical user interfaces. In Proceedings of the First International Conference on Principles and Practice of Constraint Programming, pages 624--628, Cassis, France, September 1995.

.... is also a locally error better solution [4] It is thus easier to implement algorithms to find a locally error better solution, and in particular to design hybrid algorithms that include sub solvers for simultaneous equations and inequalities and also sub solvers for non numeric constraints [3]. 1.2 Adapting the Simplex Algorithm Linear programming is concerned with solving the following problem. Consider a collection of n realvalued variables x 1 , xn , each of which is constrained to be non negative: x i # 0 for 1 # i # n. There are m linear equality or inequality ....

.... algorithms for acyclic collections of multiway constraints (e.g. 17, 19] Indigo [2] handles acyclic collections of inequality constraints, but not cycles (simultaneous equations and inequalities) UI systems that handle simultaneous linear equations include DETAIL [10] and Ultraviolet [3]. A number of researchers (including the second author) have experimented with a straightforward use of a simplex package in a UI constraint solver, but the speed was not satisfactory for interactive use. Bara# [1] describes a quadratic optimization algorithm for solving linear constraints that ....

Alan Borning and Bjorn Freeman-Benson. The OTI constraint solver: A constraint library for constructing interactive graphical user interfaces. In Proceedings of the First International Conference on Principles and Practice of Constraint Programming, pages 624--628, Cassis, France, September 1995.

.... is also a locally error better solution [4] It is thus easier to implement algorithms to find a locally error better solution, and in particular to design hybrid algorithms that include subsolvers for simultaneous equations and inequalities and also subsolvers for nonnumeric constraints [3]. Since each of these different comparators is preferable in certain situations we give algorithms for each. 1.2 Adapting the Simplex Algorithm Linear programming is concerned with solving the following problem. Consider a collection of n real valued variables x 1 ; xn , each of which ....

.... algorithms for acyclic collections of multi way constraints (e.g. 19, 21] Indigo [2] handles acyclic collections of inequality constraints, but not cycles (simultaneous equations and inequalities) UI systems that handle simultaneous linear equations include DETAIL [12] and Ultraviolet [3]. A number of researchers (including the first author) have experimented with a straightforward use of a simplex package in a UI constraint solver, but the speed was not satisfactory for interactive use. An earlier version of QOCA is described in references [10] and [11] These earlier ....

A. Borning and B. Freeman-Benson. The OTI constraint solver: A constraint library for constructing interactive graphical user interfaces. In Proc. Constraint Programming'95, Springer-Verlag LNCS Vol 910, Sep 1995.

....that can be executed repeatedly to re solve the constraints with different input parameters. We can view this as a kind of partial evaluation of the constraint solving algorithm. This has long been done for local propagation solvers (e.g. 1] and more recently for simultaneous linear equations [3] and for acyclic sets of inequality constraints [2] However, there have not been any systems that can compile plans for systems of constraints including both simultaneous equalities and inequalities. That lack is addressed by the research reported here. In brief, our algorithm works as follows. ....

....(e.g. 9, 10] or local propagation algorithms for acyclic collections of multi way constraints (e.g. 12, 15] Indigo [2] handles acyclic collections of inequality constraints, but not cycles. UI systems that handle simultaneous (cyclic) linear equations include DETAIL [8] and Ultraviolet [3]. UI systems that handle simultaneous linear inequalities as well with reasonable efficiency are QOCA [7] and Cassowary [6] Both of these algorithms are based on the simplex algorithm. We provide timing comparisons between Cassowary and our Fourier compilation algorithm in Section 5. 2 Solving ....

[Article contains additional citation context not shown here]

A. Borning and B. Freeman-Benson. The OTI constraint solver: A constraint library for constructing interactive graphical user interfaces. In Procs. of CP95, 624--628, Cassis, France, 1995.

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Borning, A., Freeman-Benson, B., The OTI Constraint Solver: A Constraint Library for Constructing Interactive Graphical User Interfaces, in: Principles and Practice of Constraint Programming - CP95 (U.Montanari, F.Rossi eds.), pp. 624-628, Cassis, France, 1995.

No context found.

Borning, A and Freeman-Benson, B: "The OTI Constraint solver: A constraint library for constructing interactive graphical user interfaces.", In Proceedings of International Conference on Principles and Practice of Constraint Programming, Cassis, France, Vol. 976, Montanari and F. Rossi, Eds., Springer-Verlag, 1995, pp 624-628.

No context found.

Borning, Alan and Bjorn Freeman-Benson, The OTI Constraint Solver: A Constraint Library for Constructing Interactive Graphical User Interfaces. In Proceedings of the First International Conference on Principles and Practice of Constraint Programming, pages 624-628, September 1995.

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