Structure

coparametrized conatural numbers object

A coparametrized conatural numbers object in a category with finite coproducts is a parametrized natural numbers object in the opposite category. This is not standard terminology and should not be confused with the set of conatural numbers studied in computer science, which dualizes natural numbers in a different way. Explicitly, a coparametrized conatural numbers object is a triple (N, z:N→0, s:N→N)(N,\, z : N \to 0,\, s : N \to N) satisfying the following universal property: for all f:X→Af : X \to A, g:X→Xg : X \to X there is a unique Φ:X→A⊔N\Phi : X \to A \sqcup N such that the diagram below commutes. X→gX→fAΦ↓↓Φi1↓∼A⊔N→idA⊔sA⊔N→idA⊔zA⊔0\begin{CD} X @>{g}>> X @>{f}>> A \\ @V{\Phi} VV @VV{\Phi}V @V{i_1}V{\sim}V \\ A \sqcup N @>>{\id_A \sqcup s}> A \sqcup N @>>{\id_A \sqcup z}> A \sqcup 0 \end{CD}

Relevant implications

Examples

There are 13 categories with this property.

Counterexamples

There are 126 categories without this property.

Unknown

There are 0 categories for which the database has no information on whether they satisfy this property.

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