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Since residue classes modulo $p$ are not numbers but sets of numbers with several operations defined on them, i don't think we can compare them at all. Yet i'm not sure.

For sake of an example lets take $p = 2$. We can claim that,

$$[0]_2 < [1]_2.$$

But wouldn't that mean any odd number is greater than any even number? Which is obviously false...

After all, if we generalize this question, does an ordered finite field exist?

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    If we want $a,b\ge 0\implies a+b\ge 0$, then $0$ can't be the sum of positive elements, therefore a field (or ring) of finite characteristic can't have a compatible order defined. – Berci Jul 25 '19 at 23:20
  • @Berci Why are you answering in a comment? – Arthur Jul 25 '19 at 23:54
  • I was lazy to look for a link of duplicate.. – Berci Jul 25 '19 at 23:55
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    Although finite fields are never ordered fields, your reasoning in the case of $p=2$ was incorrect. You wrote: "But wouldn't that mean that any odd number is greater than any even number?" No, it wouldn't mean that at all. The order relation in a field need not have anything to do with the usual ordering relation on the numbers that may be elements of elements of the field. – Andreas Blass Jul 26 '19 at 00:14
  • @Arthur It is obvious that the question is a duplicate, and repeating the same banalities as answers does not really improve the site. A comment is fine. – Jyrki Lahtonen Jul 27 '19 at 05:37

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