anchor.diff:    ssa(Expressions, Binding);
   pass(Pass, Expressions) ->
     ?MODULE:Pass(Expressions).
  +
  +%% Convert Reia instance variables into internal dict representation
  +ivars(Expressions) ->
  +  reia_ivars:ast(Expressions).
   
   %% Convert Reia forms into SSA form
   ssa(Expressions) ->
  
positive.code: -export([
    default_passes/0, 
    compile/1, 
    compile/2, 
    ssa/1, 
    r2e/1, 
    dynamic/1, 
  
negative.code: ]).
  
  default_passes() ->
    [ivars, ssa, r2e, dynamic].
  
  compile(Expressions) ->
    compile(Expressions, default_passes()).
  