The paper investigates a novel approach, based on Constraint Logic
Programming (CLP), to predict the 3D conformation of a protein via fragments
assembly. The fragments are extracted by a preprocessor-also developed for this
work- from a database of known protein structures that clusters and classifies
the fragments according to similarity and frequency. The problem of assembling
fragments into a complete conformation is mapped to a constraint solving
problem and solved using CLP.
Action description languages, such as A and B, are expressive instruments
introduced for formalizing planning domains and planning problem instances. The
paper starts by proposing a methodology to encode an action language (with
conditional effects and static causal laws), a slight variation of B, using
Constraint Logic Programming over Finite Domains. The approach is then
generalized to raise the use of constraints to the level of the action language
itself. A prototype implementation has been developed, and the preliminary
results are presented and discussed.