1. A method comprising: accepting a specification of a plurality of variables, each variable having a set of at least N possible values, wherein the plurality of variables satisfy a set of one or more constraints, and each variable is specified as a decomposition into a plurality of constituents with each constituent having a set of M possible constituent values that can be determined based on the variable values; forming a specification for configuring a computing device that implements a network representation of the constraints based on the specification of the plurality of variables, wherein the network representation includes a first set of nodes corresponding to the pluralities of constituents, a second set of nodes corresponding to the set of constraints, and interconnections between the first and the second sets of nodes for passing continuous-valued data; and wherein the computing device configured according to said specification is operable to: accept a first set of quantities each characterizing a degree of association of one constituent of one of the plurality of variables with one of the M possible constituent values; and determine a second set of quantities each characterizing a degree of association of one constituent of one of the plurality of variables with one of the M possible constituent values by passing the first set of quantities and intermediate data along the interconnections in the network representation.