  Production of pions in high-energy collisions with nuclei in the kinematics
prohibited for free nucleons ("cumulative pions") is studied in the fusing
color string model.The model describes the so-called direct mechanism for
cumulative production. The other, spectator mechanism dominates in production
of cumulative protons but is suppressed for pions. In the model cumulative
pions are generated by string fusion which raises the maximal energy of
produced partons above the level of the free nucleon kinematics. Momentum and
multiplicity sum rules are used to determine the spectra in the deep
fragmentation region. Predicted spectra of cumulative pions exponentially fall
with the scaling variable $x$ in the interval $1<x<3$ with a slope of the order
5$\div$5.6, which agrees well with the raw data obtained in the recent
experiment at RHIC with Cu-Au collisioins. However the agreement is worse for
the so-called unfolded data, presumably taking into account corrections due to
the expermental set-up and having rather a power-like form.
