Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Self-Dual Codes over Z_2xZ_4   Self-dual codes over $\Z_2\times\Z_4$ are subgroups of $\Z_2^\alpha
\times\Z_4^\beta$ that are equal to their orthogonal under an inner-product
that relates to the binary Hamming scheme. Three types of self-dual codes are
defined. For each type, the possible values $\alpha,\beta$ such that there
exist a code $\C\subseteq \Z_2^\alpha \times\Z_4^\beta$ are established.
Moreover, the construction of a $\add$-linear code for each type and possible
pair $(\alpha,\beta)$ is given. Finally, the standard techniques of invariant
theory are applied to describe the weight enumerators for each type.

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The categories of this paper are: hep-ph
7
The categories of this paper are: hep-th
23
The categories of this paper are: solv-int
25
The categories of this paper are: patt-sol
11
The categories of this paper are: hep-lat
19
The categories of this paper are: eess
36
The categories of this paper are: cmp-lg
22
The categories of this paper are: chao-dyn
4
The categories of this paper are: cond-mat
30
The categories of this paper are: q-alg
18
The categories of this paper are: econ
31
The categories of this paper are: ao-sci
9
The categories of this paper are: nlin
24
The categories of this paper are: dg-ga
3
The categories of this paper are: physics
10
The categories of this paper are: q-bio