
<ConsistencyModule:> sum(+Collection,+Rel,?Sum)

   Constrains the sum of the elements of Collection to satisfy the relation sum(Collection) Rel Sum.

Arguments
   Collection          Collection of integers or (domain) variables.
   RelOp               One of the atom: #>, #>=, #<, #=<, #=, #\=
   Sum                 (Domain) variable or integer (array notation accepted)

Type
   library(gfd)

Description
          Constrains the sum of the elements in Collection to satisfy
          the relation sum(Collection) Rel Sum.
	  
          Rel can be one of #>, #>=, #<, #=<, #=, #\= (or equivalently,
          >, >=, <, =<, =, \=).
	  
	  Any input variables which are not already domain variable will be
          turn into domain variables with default bounds.
	  
          You may find it more convenient to embed sum(Collections,RelOp) 
          in a constraint expression.
	  
          ConsistencyModule is the optional module specification to give the 
          consistency level for the propagation for this constraint: 
          gfd_bc for bounds consistency, and 
          gfd_gac for domain (generalised arc) consistency.
          
          Domain consistency is different from bounds consistency only if
          Rel is #=.
          
          This constraint is known as sum_ctr in the global constraint 
          catalog, and is implemented using Gecode's linear() constraint.
          
    

See Also
   sum / 4
