EN
$π^{i}_{j}: B_{i} → B_{ij} = B_{ji}$, i,j ∈ {1,2,3}, i ≠ j, of C*-epimorphisms assuming that it satisfies the cocycle condition. Then we show how to compute the K-groups of the multi-pullback C*-algebra of such a family, and exemplify it in the case of the triple-Toeplitz deformation of ℂP².