module Fcl_boolean:sig..end
val cstr : Fcl_var.Fd.t array -> Fcl_var.Fd.t -> Fcl_cstr.tcstr bools sum returns a constraint ensuring that sum is equal
to the sum of the boolean variables of the array bools. This constraint
posts a demon for each variable.
val sum : Fcl_var.Fd.t array -> Fcl_var.Fd.tsum bools returns the sum (a new variable) and posts the preceding
constraint.