0N9Z Theorem 2.4 ([ETW18]). The construction ⟦−⟧:ℝ3𝐋𝐢𝐧𝐤∘→𝐊b(𝐅𝐨𝐚𝐦N)\left\llbracket-\right\rrbracket\colon{\mathbb{R}}^{3}\boldsymbol{\mathrm{Link}}^{\circ}\to\boldsymbol{\mathrm{K}}^{b}(\boldsymbol{\mathrm{Foam}}_{N}) is functorial.