anchor.diff:  
   -compile(export_all).
   
  +-define(Mach_Eps, 1.1920928955078125e-7).
   -define(NotYetImplemented(Cond,Prop),?IMPLIES(not (Cond),Prop)).
   
   %% eqc_gen:sample(protobuffs_eqc:field_num()).
  
positive.code:     2;
  exp(N) ->
      2*exp(N-1).
  
  %uint(32) ->
  %    oneof([choose(0,16#ff),choose(0,16#ffff),choose(0,16#ffffff),
  %	   choose(0,16#ffffffff)]);
  %uint(64) ->
  %    oneof([uint(32),choose(0,16#ffffffffffffffff)]);
  %uint(80) ->
  %    oneof([uint(32),uint(64),choose(0,16#ffffffffffffffffffff)]).
  
  %%%%%%%%%%%%%%%%% Helper functions %%%%%%%%%%%%%%%%%%%%%%%%%%%%
  
  
negative.code:     fitbits(abs(Int),63);
  in_range(Int,uint64) ->
      fitbits(Int,64);
  in_range(Float,float) ->
      fitbits(Float,32);
  in_range(Float,double) ->
      fitbits(Float,64);
  in_range(false,bool) ->
      true;
  in_range(true,bool) ->
      true.
  
  compare(Float1, Float2) when is_float(Float1), is_float(Float2) ->
      (abs(Float1 - Float2) =< ?Mach_Eps);
  compare(A,A) -> true;
  compare(_,_) -> false.
      
  fitbits(Float,32) when is_float(Float) -> true;
  fitbits(Float,64) when is_float(Float) -> true;
  fitbits(Int,Bits) ->
      RestBits = 80-Bits,
      << NoFit:RestBits, _:Bits >> = <<Int:80>>,
  