Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: An ancient Egyptian problem:the diophantine equation 4/n=1/x+1/y+1/z,
  n>or=2   From the Rhind Papyrus and other extant sources, we know that the ancient
Egyptians were very iterested in expressing a given fraction into a sum of unit
fractions, that is fractions whose numerators are equal to 1. One of the
problems that has come down to us in the last 60 years, is known as the Erdos-
Strauss conjecture which states that for each positive integer n>1; the
fraction 4/n can be decomposed into a sum of three distinct unit fractions.
Since 1950, a numberof partial results have been achieved, see references [1]-
[8]; and also [10] and[11]. In this work we contribute four theorems. In
Theorem 2, we prove that if the fraction 4/n is not equal to a sum of three
distinct unit fractions, then each prime divisor of n; must be congruent to 1
modulo24. Moreover, if n contains a divisor noncongruent to 1mod24; then such a
decomposition does exist and it is explicitly given.

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The categories of this paper are: cmp-lg
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The categories of this paper are: q-fin
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The categories of this paper are: hep-th
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The categories of this paper are: mtrl-th
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The categories of this paper are: atom-ph
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The categories of this paper are: comp-gas
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The categories of this paper are: eess
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The categories of this paper are: solv-int
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The categories of this paper are: patt-sol
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The categories of this paper are: plasm-ph
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The categories of this paper are: nucl-th
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The categories of this paper are: funct-an
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The categories of this paper are: supr-con
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The categories of this paper are: chem-ph
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The categories of this paper are: q-alg
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The categories of this paper are: nlin