Subordinate clause, a complete sentence, a compound subject, a main clause
A prologue is merely a introduction; it cannot tell the whole story.
But a intro does tell you what is generally going to happen, that line basically means that there will be some type of internal and external conflict. Which is soon to "mend" itself (Fyi, I watched 2 Romeo and Juliet movies and read the play 3 times, if you have more questions, feel free to ask me)
Also if my first answer doesn't work try "This prologue does not disclose all the juicy details of the story
The prosecutor is trying to prove that Mersault has committed premeditated murder in the death of the Arab man.
The prosecutor is showing that Mersault did not feel badly about his mother's death. He didn't grieve for her which is evidenced by his napping at her funeral. He wants to show that this absence of grief is a sign of moral depravity and that is a threat to society. The moral decay that Mersault shows by not being upset demonstrates his guilt and warrants the death penalty.
We can't see the whole paper so we may not know if there are more words..