%metta_atom_iter(Eq,Depth,_Slf,Other,X):- dcall0000000000(eval_args_true(Eq,_RetType,Depth,Other,X)).
metta_atom_iter(Eq,Depth,Self,Other,X):-
  %copy_term(X,XX),
  dcall0000000000(metta_atom_true(Eq,Depth,Self,Other,X)). %, X=XX.

metta_atom_true(_Eq,Depth,Self,Other,H):-
      can_be_ok(metta_atom_true,H),
      into_space(Depth,Self,Other,Space),
      metta_atom(Space,H).
% is this OK?
%metta_atom_true(Eq,Depth,Self,Other,H):- nonvar(H), metta_eq_def(Eq,Other,H,B), D2 is Depth -1, eval_args_true(Eq,_,D2,Self,B).
% is this OK?
%metta_atom_true(Eq,Depth,Self,Other,H):- Other\==Self, nonvar(H), metta_eq_def(Eq,Other,H,B), D2 is Depth -1, eval_args_true(Eq,_,D2,Other,B).



eval_args_true_r(Eq,RetType,Depth,Self,X,TF1):-
  ((eval_ne(Eq,RetType,Depth,Self,X,TF1),  \+  is_False(TF1));
     ( \+  is_False(TF1),metta_atom_true(Eq,Depth,Self,Self,X))).

eval_args_true(Eq,RetType,Depth,Self,X):-
 % can_be_ok(eval_args_true,X),
 % metta_atom_true(Eq,Depth,Self,Self,X);
   (nonvar(X),eval_ne(Eq,RetType,Depth,Self,X,TF1),  \+  is_False(TF1)).


metta_atom_iter_ref(Other,H,Ref):-clause(metta_atom_asserted(Other,H),true,Ref).
can_be_ok(A,B):- cant_be_ok(A,B),!,fbug(cant_be_ok(A,B)),trace.
can_be_ok(_,_).

cant_be_ok(_,[Let|_]):- Let==let.
% =================================================================
% =================================================================
% =================================================================
%  CASE/SWITCH
% =================================================================
% =================================================================
% =================================================================
% Macro: case
:- nodebug(metta(case)).

eval_20(Eq,RetType,Depth,Self,['switch',A,CL|T],Res):- !,
  eval_20(Eq,RetType,Depth,Self,['case',A,CL|T],Res).

eval_20(Eq,RetType,Depth,Self,[P,X|More],YY):- is_list(X),X=[_,_,_],simple_math(X),
   eval_selfless_2(X,XX),X\=@=XX,!, eval_20(Eq,RetType,Depth,Self,[P,XX|More],YY).
% if there is only a void then always return nothing for each Case
eval_20(Eq,_RetType,Depth,Self,['case',A,[[Void,_]]],Res):-
   '%void%' == Void,
   eval_args(Eq,_UnkRetType,Depth,Self,A,_),!,Res =[].

% if there is nothing for case just treat like a collapse
eval_20(Eq,RetType,Depth,Self,['case',A,[]],NoResult):- !,
  %forall(eval_args(Eq,_RetType2,Depth,Self,Expr,_),true),
  once(eval_args(Eq,_RetType2,Depth,Self,A,_)),
  make_nop(RetType,[],NoResult).


into_case_keys(_,[],[]).
into_case_keys(Nth,[Case0|CASES],[Key-Value|KVs]):-
  Nth1 is Nth+1,
  is_case(Key,Case0,Value),
  if_trace((case),(format('~N'),writeqln(c(Nth,Key)=Value))),
  into_case_keys(Nth1,CASES,KVs).

% Macro: case
eval_20(Eq,RetType,Depth,Self,['case',A,CL|T],Res):- !,
   must_det_ll(T==[]),
   into_case_list(CL,CASES),
   into_case_keys(1,CASES,KVs),
   eval_case(Eq,RetType,Depth,Self,A,KVs,Res).

eval_case(Eq,CaseRetType,Depth,Self,A,KVs,Res):-