The left internal Hom of pointed sets is the functor

\[ \webleft [-,-\webright ]^{\lhd }_{\mathsf{Sets}_{*}}\colon \mathsf{Sets}^{\mathsf{op}}_{*}\times \mathsf{Sets}_{*}\to \mathsf{Sets}_{*} \]

defined as the composition

\[ \mathsf{Sets}^{\mathsf{op}}_{*}\times \mathsf{Sets}_{*}\overset {{\text{忘}}\times \mathsf{id}}{\to }\mathsf{Sets}^{\mathsf{op}}\times \mathsf{Sets}_{*}\overset {\pitchfork }{\to }\mathsf{Sets}_{*}, \]

where:

  • ${\text{忘}}\colon \mathsf{Sets}_{*}\to \mathsf{Sets}$ is the forgetful functor from pointed sets to sets.
  • $\pitchfork \colon \mathsf{Sets}^{\mathsf{op}}\times \mathsf{Sets}_{*}\to \mathsf{Sets}_{*}$ is the cotensor functor of Item 1 of Proposition 5.2.2.1.4.

For a proof that $\webleft [-,-\webright ]^{\lhd }_{\mathsf{Sets}_{*}}$ is indeed the left internal Hom of $\mathsf{Sets}_{*}$ with respect to the left tensor product of pointed sets, see Item 2 of Proposition 5.3.1.1.7.


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