  Let $M$ be a smooth manifold, smoothly triangulated by a simplicial complex
$K$, and $\cA$ a transitive Lie algebroid on $M$. The Lie algebroid restriction
of $\cA$ to a simplex $\Delta$ of $K$ is denoted by $\cA^{!!}_{\Delta}$. A
piecewise smooth form of degree $p$ on $\cA$ is a family
$\omega=(\omega_{\Delta})_{\Delta\in K}$ such that $\omega_{\Delta}\in
\Omega^{p}(\cA^{!!}_{\Delta};\Delta)$ for each $\Delta\in K$, satisfying the
compatibility condition concerning the restrictions of $\omega_{\Delta}$ to the
faces of $\Delta$, that is, if $\Delta'$ is a face of $\Delta$, the restriction
of the form $\omega_{\Delta}$ to the simplex $\Delta'$ coincides with the form
$\omega_{\Delta'}$. The set $\Omega^{\ast}(\cA;K)$ of all piecewise smooth
forms on $\cA$ is a cochain algebra. One has a natural morphism
$$\Omega^{\ast}(\cA;M)\rightarrow \Omega^{\ast}(\cA;K)$$ of cochain algebras
given by restriction of a smooth form defined on $\cA$ to a smooth form defined
on $\cA^{!!}_{\Delta}$, for all simplices $\Delta$ of $K$. In this paper, we
prove that, for triangulated compact manifolds, the cohomology of this
construction is isomorphic to the Lie algebroid cohomology of $\cA$, in which
the isomorphism is induced by the restriction map.
