More more astute and present will always punish the tardy for posting too soon, I was in the process of supplying more context while you posted.
A fuller rendering of T1564.23c16 Āryanāgārjunasya Mūlamadhyamakakārikāyām Ātmaparīkṣā is
All Buddhas either speak of self or speak of no self.
All dharmas’ true aspect, within this, there is neither self nor no self.
All dharmas’ true aspect is defined as mental activity’s and spoken language’s ending.
There is no arising and no cessation, there is calm extinction, such is nirvāṇa.
All is real, all is unreal, all is both real and unreal,
all is neither real nor unreal: this is called all Buddhas’ dharma.
Example 1:
darśanaśravaṇādīni vedanādīni cāpyatha |
bhavanti yasya prāg ebhyaḥ so’stītyeke vadantyuta ||
kathaṃ hyavidyamānasya darśanādi bhaviṣyati |
bhāvasya tasmāt prāg ebhyaḥ so’sti bhāvo vyavasthitaḥ ||
darśanaśravaṇādibhyo vedanādibhya eva ca |
yaḥ prāg vyavasthito bhāvaḥ kena prajñapyate’tha saḥ ||
vināpi darśanādīni yadi cāsau vyavasthitaḥ |
amūnyapi bhaviṣyanti vinā tena na saṃśayaḥ ||
ajyate kenacit kaścit kiṃcit kena cid ajyate |
kutaḥ kiṃcid vinā kaścit kiṃcit kiṃcid vinā kutaḥ ||
sarvebhyo darśanādibhyaḥ kaścit pūrvo na vidyate |
ajyate darśanādinām anyena punar anyadā ||
sarvebhyo darśanādibhyo yadi pūrvo na vidyate |
ekaikasmāt kathaṃ pūrvo darśanādeḥ sa vidyate ||
draṣṭā sa eva sa śrotā sa eva yadi vedakaḥ |
ekaikasmād bhavet pūrvam evaṃ caitan na yujyate ||
draṣṭānya eva śrotānyo vedako’nyaḥ punar yadi |
sati syād draṣṭari śrotā bahutvaṃ cātmanāṃ bhavet |
Example 2:
ātmetyapiprajñapitam anātmetyapideśitam |
buddhair nātmā nacānātmā kaścid ityapi deśitam ||
nivṛttam abhidhātavyaṃ nivṛttaś cittagocaraḥ |
anutpannāniruddhā hi nirvāṇam iva dharmatā ||
sarvaṃ tathyaṃ na vā tathyaṃ tathyaṃ cātathyam eva ca |
naivātathyaṃ naiva tathyam etad buddhānuśāsanam ||