virt_sizo(Sizo):-
  bind_scope(_, assign_sizo(Sizo), strong).

virt_resource(files).
  
virt_sizo_control(Sizo, Resource):-
  bind_scope(Scope, assign_sizo_control(Resource), strong);
  bind_scope(Scope, assign_sizo(Sizo), strong).

%   Decisions
%----------------------------------- 
virt_sizo_strategy(Sizo, Resource, direct):-
  not virt_sizo_control(Sizo, Resource);
  virt_resource(Resource);
  virt_sizo(Sizo).

activate_strategy_prefix(prefix) :- 
  2 #count{Sizo: virt_sizo_control(Sizo, files)}.
  
virt_sizo_strategy(Sizo, files, prefix):-
    activate_strategy_prefix(prefix);
    virt_sizo_control(Sizo, files);
    not decided(virt_strategy(Sizo, files), 2).

virt_sizo_strategy(Sizo, Resource, common):-
  virt_sizo_control(Sizo, Resource);
  not virt_sizo_strategy(Sizo, Resource, prefix);
  not decided(virt_strategy(Sizo, files), 2).

  
dict_sizo(Sizo, Id):-
    Id= #sum{ 1, SizoLess : virt_sizo(SizoLess), SizoLess < Sizo};
    virt_sizo(Sizo).
    
%   Connect to Latex
%-----------------------------------  
latex_registered_subjects(sizo, Sizo):- virt_sizo(Sizo).

latex_scope_demand(ScopeDemandSizo, sizo):- 
  bind(Target, demand(sizo));
  Target = s(_, _, ScopeDemandSizo).
  
bind_scope(Scope, Sizo, strong):-
  bind_scope(Scope, assign_sizo(Sizo), strong).
 
%   Polymorphism based on virtualizaion strategy
%-----------------------------------  
dfa_callguard(SymbRet, strategy(Strategy)):-
  dfa_callfn(SymbRet, Fn);
  bind_func(Fn, assign_zek_access(Resource));
  SymbRet = s(_, _, Scope);
  bind_scope(Scope, assign_sizo(Sizo), strong);
  virt_sizo_strategy(Sizo, Resource, Strategy).
  
late(SymbRet, SymbolSizo, Sizo, dfa_callguard(SymbRet, strategy(Strategy))):-
  bind_func(FnName, assign_zek_access(Resource));
  virt_sizo_strategy(Sizo, Resource, Strategy);
  
  dfa_callfn(SymbRet, FnName);
  SymbRet=s(_, _, ScopeCaller);
  scope_fnbody(ScopeCaller, FnCallerBody);
  latex_symbol(FnCallerBody, sizo, SymbolSizo);
  virt_sizo(Sizo).