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Date: 26-5-2021
1477
Date: 27-6-2021
1483
Date: 2-8-2021
1095
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A species of structures is a rule which
1. Produces, for each finite set , a finite set ,
2. Produces, for each bijection , a function
(1) |
The functions should further satisfy the following functorial properties:
1. For all bijections and ,
(2) |
2. For the identity map ,
(3) |
An element is called an -structure on (or a structure of species on ). The function is called the transport of -structures along .
REFERENCES:
Bergeron, F.; Labelle, G.; and Leroux, P. Combinatorial Species and Tree-Like Structures. Cambridge, England: Cambridge University Press, p. 5, 1998.
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مكتبة أمّ البنين النسويّة تصدر العدد 212 من مجلّة رياض الزهراء (عليها السلام)
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