  The purpose of this paper is to study $\mathcal{P}\mathcal{R}$-semi-invariant
warped product submanifolds of a paracosymplectic manifold $\widetilde{M}$. We
prove that the distributions associated with the definition of
$\mathcal{P}\mathcal{R}$-semi-invariant warped product submanifold $M$ are
always integrable. A necessary and sufficient condition for an isometrically
immersed $\mathcal{P}\mathcal{R}$-semi-invariant submanifold of $\widetilde{M}$
to be a $\mathcal{P}\mathcal{R}$-semi-invariant warped product submanifold is
obtained in terms of the shape operator.
