DN 1 states the view of nihilist wanderers, as follows:

Herein, bhikkhus, a certain recluse or a brahmin asserts the following doctrine and view: ‘The self, good sir, has material form; it is composed of the four primary elements and originates from father and mother. Since this self, good sir, is annihilated and destroyed with the breakup of the body and does not exist after death, at this point the self is completely annihilated.’ In this way some proclaim the annihilation, destruction, and extermination of an existent being.

Is the word 'self' used here in conventional language?

Or does the word 'self' here actually represent a belief in self by those nihilist wanderers?

If those nihilist wanderers did not believe in 'self', why were they not enlightened?

DN 1 states the view of nihilist wanderers, as follows:

Herein, bhikkhus, a certain recluse or a brahmin asserts the following doctrine and view: ‘The self, good sir, has material form; it is composed of the four primary elements and originates from father and mother. Since this self, good sir, is annihilated and destroyed with the breakup of the body and does not exist after death, at this point the self is completely annihilated.’ In this way some proclaim the annihilation, destruction, and extermination of an existent being.

Is the word 'self' used here in conventional language?

Or does the word 'self' here actually represent a belief in self by those nihilist wanderers?

If those nihilist wanderers did not believe in 'self' ( and thus used 'conventional language'), why were they not considered to be enlightened?