Logic Programming Based
Model Transformations
An overview of related work
GOAL – WHY?
• Exploring the reasoning techniques for
querying the inconsistencies in Models and
model transformations
• State of the art, challenges, gaps and how we
can contribute
• Simplify transformations between ISO and
CCOM
Logic programming
language
Answer Set Programming (ASP)
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Declarative
Search problems to find stable models
answer set solvers — programs for generating
stable models—are used to perform search
Alloy
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lightweight formal specification language
declarative based on first-order logic
based on relational logic > effective to validate
and verify object-oriented models
automatic model finding via SAT solving
Alloy model consists of Signatures, Relations,
Facts and Predicates.
Alloy Analyzer (Simulation & Assertion)
Prolog
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first-order logic
relations represents facts and rules. A
computation is initiated by running a query over
these relations
RELATED WORK
Antonio Cicchetti, Davide Ruscio, Romina Eramo, and Alfonso Pierantonio. JTL:
A Bidirectional and Change Propagating Transformation Language. In SLE
2011, volume LNCS 6563, pages 183-202. Springer, 2011.
Johannes Schoenboeck, Angelika Kusel, Juergen Etzlstorfer, Elisabeth
Kapsammer, Wieland Schwinger, Manuel Wimmer, and Martin Wischenbart.
CARE - A Constraint-Based Approach for Re-Establishing Conformance
Relationships. In APCCM 2014, CRPIT Vol.154, pages 19-28. ACS, 2014
Anastasakis, K., Bordbar, B., & Küster, J. M. (2007, October). Analysis of model
transformations via Alloy. In Proceedings of the 4th MoDeVVa workshop
Model-Driven Engineering, Verification and Validation (pp. 47-56).
Nuno Macedo and Alcino Cunha. Implementing QVT-R bidirectional model
transformations using Alloy. In Fundamental Approaches to Software
Engineering, pages 297-311. Springer, 2013.
Zoltan Balogh and Daniel Varro. Model transformation by example using
inductive logic programming. SoSyM, 8(3):347-364, 2009.
JesusM. Almendros-Jimenez and Luis Iribarne. A model transformation
language based on logic programming. In SOFSEM 2013, volume LNCS 7741,
pages 382-394. Springer, 2013.
CARE approach(ASP)
• Each metamodel elements > class, attribute and reference ASP facts.
• Model elements > object, value and link ASP facts.
• Conformance constrains have been manually defined [in pseudocode in
table] and encoded in ASP.
• Meta-model specific Ecore/OCL constrains > ASP constrains in future
version of prototype.
• Language semantics(object-oriented) need to be encoded as well.
• Ecore <> ASP transformations are implemented by Xtend (a flexible and
expressive dialect of Java)
• A constraint solver produces an output, which is a set of facts describing
which objects, values, and links are conform or not, and adds these new
facts to the CARE knowledge base.
JTL approach(ASP)
• Modeled as Graphs composed of nodes, edges and properties – logic
assertions
• (1)Each (meta)model elements > metanode, metaedge, and metaprop
predicate symbols
• (1)Each model element > node, edge, property
• (2)JTL(QVT-R like syntax) > ASP relation and constrains by means of ATL
transformation
• (4)Transformation (JTL) engine is based on ASP bidirectional
transformation program executed by DLV solver(find stable models)
Transformation process steps:
1. the execution engine induces all the possible solution candidates according
to the specified relations;
2. the set of candidates is refined by means of constraints (ASP rules).
(3)Target model is deducted based on ASP rules from candidate solutions.
Analysis of MT(Alloy)
• based on meta-modelling
• MOF meta-models/OCL > Alloy by means of UML2Alloy transformation
tool
• Transformation rules > Alloy mapping relation
• STEPS
Step 1:Translate the Model Transformation Specification to Alloy.
Step 2: Analysis using the Alloy Analyzer.
• Alloy model of MT which can be analysed by Analyzer(Simulation)
QVT-R Bidirectional (Alloy)
• UML(annotated with OCL) + QVT-R > Alloy
• principle of least change restores consistency by simply returning target
models that are at a minimal distance from the original -> the“checkbefore-enforce” policy (QVT-R) is satisfied.
• Classes and associations (including attributes) > signatures and relations in
Alloy. Inheritance relationship in Alloy.
• For each relation R > Alloy predicates to specify Rforward and Rbackward
• Predicates are used to specify the when and where clauses, and the
domain patterns of each relation
• checkonly mode - check the consistency predicate for a pair of models
PTL approach(Prolog)
• Each (meta) model elements > set of classes, attributes, roles and helpers.
• Each model elements > set of classes, attributes, roles, helpers and
objects.
• PTL > Prolog encoding - based on a Prolog library for handling metamodels
• PTL (ATL like syntax) = ATL style rules + logic Rules in Prolog(helpers).
Prolog style rules serve as a query language. Prolog is used as a
transformation engine for PTL.
• A Prolog program is automatically obtained from a PTL program. The
encoding of PTL programs with Prolog is based on a Prolog library for
handling meta-models
Inductive logic(Prolog)
• Modeled as Graphs composed of nodes, edges and properties – logic
assertions
• Source and target models are mapped into Prolog clauses
• Mapping models are represented by tuples
ref (ri , src1, . . . , srcn, trg1, . . . , trgm).
Conclusions
• Logic clause, fact, assertion = represents models and
meta-models
• Logic rule = used to encode model transformation and
constraints on models
• taking advantage of model finding(SAT-solver) abilities
• Being solver-based, the main drawback is performance
- incremental solving techniques
- mechanisms to infer which parts of target model can be fixed in design time
• Model & transformation > logic programming is manual,
except in JTL approach