New Features in library(clpfd)

• fd_degree/2 is new; returns the number of constraints attached to a variable.
• labeling/2 requires the list of domain variables to have bounded domains. User-defined variable and value choice heuristics can be provided.
• element/3 is interval-consistent in its second and third arguments. Use relation/3 if domain-consistency is required.
• serialized/3 is new and replaces serialized_precedence/3 and serialized_precedence_resource/4. A number of new options control the algorithm. The space complexity no longer depends on the domain size.
• cumulative/5 is new and takes the same options as serialized/3.
• all_different/2, all_distinct/2 and assignment/3 are new and take options controlling the algorithms.
• Generally, performance and error checking have been improved.