1. A computer-implemented method performed by a computerized device, comprising: obtaining a Constraint Satisfaction Problem (CSP) comprising a set of variables, a set of corresponding domains, and a set of constraints; solving the CSP by iteratively: limiting the domains to exclude values that cannot satisfy one or more constraints of the set of constraints; heuristically selecting a variable out of the set of variables, wherein said heuristically selecting is based on constraint semantics of a constraint of the set of constraints, wherein said heuristically selecting the variable based on constraint semantics comprises: identifying in the constraint a decidable operator connecting at least a sub-constraint and an additional sub-constraint; and selecting the variable from the sub-constraint; and limiting a corresponding domain of the variable.