Sets and relations are taught in modern algebra. One of them, character encoding, is used in computers today.
In computing, data storage, and data transmission, character encoding is used to represent a repertoire of characters by some kind of encoding system that assigns a number to each character for digital representation.
We can represents one set of characters instead of another. This was known recently, however this was portrayed in the Quran 1400 years before it was discovered. Some verses in the Quran contain letters that have no meaning in Arabic however they seem to be encoded. In chapter 27 it starts with "T ط" and "S س":
"T ط" occurs 27 times in this chapter, same number of the chapter 27.
"S س" occurs 93 times in this chapter, same number of verses 93.
From Quran Characters Counter:
In chapter 27, "T ط" occurs 27 times and "S س" occurs 93 times.
This chapter is number 27, but the Quran was arranged after the prophets' death so he couldn't have known that this chapter will be number 27; and yet number 27 is encoded in the letters.
If "T ط" is 27 and "S س" is 93 then Quran T:S says that you will see God's signs and you will recognize them:
٩٣ وَقُلِ الْحَمْدُ لِلَّهِ سَيُرِيكُمْ آيَاتِهِ فَتَعْرِفُونَهَا ۚ وَمَا رَبُّكَ بِغَافِلٍ عَمَّا تَعْمَلُونَنَ
How could an illiterate man who lived 1400 years ago have known about character encoding?
The Quran (Koran, the book of Islam) contains scientific knowledge that could not have been known 1400 years ago. It ranges from basic arithmetics to the most advanced topics in astrophysics. You are invited to go through those miracles and judge for yourself.