| 20-XX |
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|
Group theory and generalizations |
|
20Nxx |
|
Other generalizations of groups |
|
|
20N02 |
Sets with a single binary operation (groupoids) {For groupoids in connection with category theory, see 20L05; for topological groupoids, see 22A22, 58H05} |
|
|
20N05 |
Loops, quasigroups [See also 05Bxx] |
|
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20N10 |
Ternary systems (heaps, semiheaps, heapoids, etc.) |
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20N15 |
$n$-ary systems $(n\ge 3)$ |
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|
20N20 |
Hypergroups |
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20N25 |
Fuzzy groups [See also 03E72] |
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|
20N99 |
None of the above, but in this section |
