NOTE:When there are no registered visualisation clients, this predicate succeeds with any arguments, and has no effect.
This predicate creates a new viewable by specifying its name, elements and type. At present the type must be of the form array(FixityList, ElementType) or graph(fixed) wherefixed or
	flexible specifying the fixity for each
	dimension. The fixity denotes whether the dimension's size is
	fixed or may vary during the time when the viewable is
	existent.any
	which includes any ECLiPSe termnumeric_bounds which includes any ground number,
	integer fd variables, ic variables
	and range variables (including eplex
	and ria variables). changeable(Module,Type) which indicates that the
	value should be accessed through the changeable
	interface of the given Module
	(eg. changeable(eplex_instance,any) indicates that the value
	is ths solution assigned to the variable by the given
	eplex_instance).  The Type parameter can be any
	of the other ElementTypes in this list.viewable_create/3, the viewable is destroyed, and
	visualisation clients are also notified of this. ViewableName is a global handle which can be used to access the viewable while it is existent. If ViewableName is a variable, it is instantiated to an atom. The atom is unique in the sense that no two existent viewables will share the same name at any point during the lifetime of the ECLiPSe engine.
        For array types, the number of dimensions is specified by the
        length of FixityList in Type. Elements
        is a nested list or array. The depth of nesting is usually at
        least the number of dimensions specified in FixityList.
        However, dimensions with an initial size of 0 are also
        allowed, and these can implicitly contain an arbitrary number
        of further dimensions, also assumed to be of initial size
        0. So for example an Elements argument of
        [[],[],[]] or []([],[],[]) can be
        used with a FixityList of [fixed,
        flexible], giving an initial size of 3 x 0, or used
        with a FixityList of [fixed, flexible,
        flexible, flexible], giving an initial size of 3 x 0 x
        0 x 0. Be sure to make any initially empty dimensions
        flexible!  Elements must also be regular: each inner
        list / array at the same level of nesting must be the same
        length, down to the level equal to the number of dimensions.
        
viewable_create/3 sets location names (e.g. row/column
        names) to "1", "2", etc. For more control over location names use 
        viewable_create/4.
[Assuming that at least one visualisation client is registered] 
       Success:
       viewable_create(viewable1, [X, Y, Z], array([fixed], any)).
       lib(fd), fd:([X, Y, Z]::1..10), 
       viewable_create(viewable1, [X, Y, Z], array([fixed], numeric_bounds)).
       viewable_create(viewable1, [3.2, 5.00__5.01, 7], 
                       array([fixed], numeric_bounds)).
       viewable_create("viewable1", [](X, Y, Z), array([flexible], any)).
       viewable_create(m, [], array([flexible], any)).
       viewable_create(var23, [[],[],[]], array([fixed, flexible], any)).
       viewable_create(var315, []([]([](R, T, [E, X, Y]), 
                                     [](W, T, grok(D))), 
				  []([](A, B, C),
				     [](R, E, W))), 
		       array([fixed, flexible, flexible], any)).
       viewable_create(m,[[],[],[]],array([fixed, flexible, flexible],any)).
       [Note: the initial size of this viewable would be 3 x 0 x 0]
       lib(graph_algorithms),
       make_graph(3,[e(1,2,e1), e(2,3,e2), e(1,3,e3)], Graph),
       viewable_create(m, Graph, graph(fixed)).
       [Note: the node will be labelled with the numbers '1', '2' and '3',
       the edges labelled 'e1', 'e2' and 'e3']
       
       lib(graph_algorithms),
       make_graph_symbolic([](n1,n2,n3),[edge(n1,n2,e1), edge(n2,n3,e2), edge(n1,n3,e3)], Graph),
       viewable_create(m, Graph, graph(fixed)).
       [Note: the node will be labelled with the strings 'n1', 'n2' and 'n3',
       the edges labelled 'e1', 'e2' and 'e3']
       lib(eplex_with_ic),
       eplex_instance(my_instance),
       my_instance: eplex_solver_setup(min(X)),
       viewable_create(eplex,[X,Y],array([fixed],changeable(my_instance,numeric_bounds))),
       viewable_create(ic,[X,Y],array([fixed],numeric_bounds)),
       my_instance: (X+Y >= 3),
       my_instance: (X-2*Y =:= 0),
       my_instance: eplex_solve(Cost).       
       [Note: this creates two viewables, one showing the solution as
        assigned by eplex, the other showing the ic bounds]
       lib(s_eplex),
       eplex_instance(my_instance),
       my_instance: eplex_solver_setup(min(X)),
       viewable_create(eplex,[X,Y],array([fixed],changeable(my_instance,numeric_bounds))),
       my_instance: (X+Y >= 3),
       my_instance: (X-2*Y =:= 0),
       my_instance: eplex_solve(Cost).       
       [Note: this creates a single viewable using the standalone eplex
        library and shows how to visualise the bounds stored in the external
        solver]
       Exceptions raised:
       viewable_create(2, [x,y,z], array([fixed], any)).
       [gives error 4] 
       viewable_create(v1, [x,y,z], array([fixed], any)), 
       viewable_create(v1, [x,y,z], array([fixed], any)).
       [gives error 1] 
       viewable_create(v1, _, array([fixed], any)).
       [gives error 1] 
       viewable_create(v1, [x,y,g], array([fixed, fixed], any)).
       [gives error 1] 
       viewable_create(v1, [x,y,x], array([], any)).
       [gives error 1] 
       viewable_create(v1, [x,y,x], slorg([fixed], any)).
       [gives error 1] 
       viewable_create(v1, [x,y,x], nurg).
       [gives error 1] 
       viewable_create(v1, [x,y,x], numeric_bounds).
       [gives error 5]