anchor.diff:  	    X < Y).
   
   
  -
  +tuple_failure_test() ->
  +    false = check(?FORALL(T, {int()},
  +			  begin
  +			      {V} = T,
  +			      V > 0
  +			  end)).
  
positive.code: 		 ==
  		 lists:reverse(Ys) ++ lists:reverse(Xs))).
  					 
  prop_delete() ->
    fails(
      ?FORALL(L,list(int()), 
  	?IMPLIES(L /= [],
  	    ?FORALL(I,elements(L), 
  
negative.code: inverse('/=') -> '=='.
  
  prop_binop() ->
      ?FORALL({A,B,OP}, {any(),any(),elements(['>','<','==','=:=','=/=','/='])},
  	    erlang:OP(A,B) 
  	    ==
  	    begin 
  