Solving loosely coupled constraints

Many practical problems are modelled by mean of constraints which, pairwise, share only a few variables if any. Suc constraints are loosely coupled. In this paper we show how to use this property to lower the complexity of decision procedures or solvers. The introduction of a data structure, the well formed covering tree allows for a reparametrisation of constraint problems in a way which can be seen as a generalisation of the triangulation procedure for system of linear equations