-module(para1).
-compile(export_all).
%% Parameterized opaque types
-export_type([t/0, t/1]).
-opaque t() :: {integer(), integer()}.
-opaque t(A) :: {A, A}.
-type y(A) :: {A, A}.
tt1() ->
I = t1(),
A = t2(),
A =:= I. % never 'true'
tt2() ->
I = t0(),
A = t2(),
A =:= I. % never 'true'
tt3() ->
I1 = t0(),
I2 = t1(),
I1 =:= I2. % never true
tt4() ->
I1 = y1(),
I2 = y2(),
I1 =:= I2. % cannot evaluate to true
adt_tt1() ->
I = adt_t1(),
A = adt_t2(),
A =:= I. % opaque attempt
adt_tt2() ->
I = adt_t0(),
A = adt_t2(),
A =:= I. % opaque attempt
adt_tt3() ->
I1 = adt_t0(),
I2 = adt_t1(),
I1 =:= I2. % opaque attempt
adt_tt4() ->
I1 = adt_y1(),
I2 = adt_y2(),
I1 =:= I2. % cannot evaluate to true
-spec t0() -> t().
t0() ->
{3, 2}.
-spec t1() -> t(integer()).
t1() ->
{3, 3}.
-spec t2() -> t(atom()).
t2() ->
{a, b}.
-spec y1() -> y(integer()).
y1() ->
{3, 2}.
-spec y2() -> y(atom()).
y2() ->
{a, b}.
adt_t0() ->
para1_adt:t0().
adt_t1() ->
para1_adt:t1().
adt_t2() ->
para1_adt:t2().
adt_y1() ->
para1_adt:y1().
adt_y2() ->
para1_adt:y2().
