anchor.diff:  -export([
     default_passes/0, 
     compile/1, 
  -  compile/2, 
  +  compile/2,
  +  ivars/1, 
     ssa/1, 
     r2e/1, 
     dynamic/1, 
  
positive.code: ]).
  
  default_passes() ->
    [ssa, r2e, dynamic].
  
  compile(Expressions) ->
    compile(Expressions, default_passes()).
  
negative.code:   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) ->
  