anchor.diff:                  [{"F", {b_abs, [], ["x", "y"],
                           {primop, _, ["x", "y"]}}}]},
                  _BAbsT0 = t0(s(S))),
  -  {setup, fun setup/0, fun cleanup/1,
  +  {foreach, fun setup/0, fun cleanup/1,
      [ ?_assertMatch({45,_}, eval(S)) ]}.
   
   b_abs_nested_in_wheredim_does_not_cause_wrong_substitution() ->
  
positive.code:       fun F.x.y = x - y
        fun G.x = F
      end",
    {setup, fun setup/0, fun cleanup/1,
     [ ?_assertMatch({43,_}, eval(S)) ]}.
  
  b_abs_can_access_formal_params_of_outer_b_abs() ->
  
negative.code:           }}]},
         [{WheredimX,46}]},
       t1(t0(s(S)))),
    {foreach, fun setup/0, fun cleanup/1,
     [ ?_assertMatch({47,_}, eval(S)) ]}.
  
  wheredim_nested_in_b_abs_does_not_cause_wrong_substitution() ->
  