Structure

category of combinatorial species

Notation Sp\Sp Objects combinatorial species, defined as functors B→FinSet\IB \to \FinSet, where B\IB is the category of finite sets and bijections Morphisms natural transformations Related B\IB, FinSet\FinSet, M−SetM{-}\Set External nLab link
Most categorical properties are immediately inferred from FinSet\FinSet. Notice that this category is not locally small; it is just equivalent to a locally small category.

Satisfied properties

Assigned properties

Deduced properties

Unsatisfied properties

Assigned properties

Deduced properties*

*This also uses the deduced satisfied properties.

Unknown properties

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Special objects

  • terminal object: species XX with Xn={∗}X_n = \{\ast\}
  • initial object: species XX with Xn=∅X_n = \varnothing
  • products: [finite case] pointwise defined direct product
  • coproducts: [finite case] pointwise finite disjoint union

Special morphisms