7.2.2 Agreement principle

• identifier: principle.agreement
• dimension variables: D
• argument variables:
  Agr1: tv(T)
Agr2: tv(T)
Agree: set(label(D))
• default values:
  Agr1: ^.D.attrs.agr
Agr2: _.D.attrs.agr
Agree: ^.D.entry.agree
• model record: empty
• constraints: Agreement (priority 100)
• edge constraints: none

This principle assumes that the Graph principle (Graph) is used on dimension D.

The Agreement principle establishes agreement between the nodes connected by an edge.

It stipulates that:

• for all edges labeled l, if l is in Agree, then Agr1=Agr2

Here is the definition of the Agreement constraint functor:

%% Copyright 2001-2008
%% by Ralph Debusmann <rade@ps.uni-sb.de> (Saarland University) and
%%    Denys Duchier <duchier@ps.uni-sb.de> (LIFO, Orleans) and
%%    Jorge Marques Pelizzoni <jpeliz@icmc.usp.br> (ICMC, Sao Paulo) and
%%    Jochen Setz <info@jochensetz.de> (Saarland University)
%%
functor
import
   Helpers(checkModel) at 'Helpers.ozf'
   Opti(isIn) at 'Opti.ozf'
export
   Constraint
define
   proc {Constraint Nodes G Principle FD FS Select}
      DVA2DIDA = Principle.dVA2DIDA
      ArgRecProc = Principle.argRecProc
      %%
      DIDA = {DVA2DIDA 'D'}
      DIDA2LabelLat = G.dIDA2LabelLat
      LabelLat = {DIDA2LabelLat DIDA}
      LAs = LabelLat.constants
   in
      %% check features
      if {Helpers.checkModel 'Agreement.oz' Nodes
	  [DIDA#daughtersL]} then
	 for Node1 in Nodes do
	    for Node2 in Nodes do
	       for LA in LAs do
		  if {Not {Opti.isIn Node2.index Node1.DIDA.model.daughtersL.LA}=='out'} then
		     LI = {LabelLat.aI2I LA}
		     %%
		     AgreeLM = {ArgRecProc 'Agree' o('^': Node1
						     '_': Node2)}
		     Agr1D = {ArgRecProc 'Agr1' o('^': Node1
						  '_': Node2)}
		     Agr2D = {ArgRecProc 'Agr2' o('^': Node1
						  '_': Node2)}
		  in
		     {FD.impl
		      {FS.reified.include Node2.index Node1.DIDA.model.daughtersL.LA}
		      {FD.impl
		       {FS.reified.include LI AgreeLM}
		       {FD.reified.equal Agr1D Agr2D}} 1}
		  end
	       end
	    end
	 end
      end
   end
end