  In this study, we model a sequence of a confined and a full eruption,
employing the relaxed end state of the confined eruption of a kink-unstable
flux rope as the initial condition for the ejective one. The full eruption, a
model of a coronal mass ejection, develops as a result of converging motions
imposed at the photospheric boundary, which drive flux cancellation. In this
process, parts of the positive and negative external flux converge toward the
polarity inversion line, reconnect, and cancel each other. Flux of the same
amount as the canceled flux transfers to a flux rope, increasing the free
magnetic energy of the coronal field. With sustained flux cancellation and the
associated progressive weakening of the magnetic tension of the overlying flux,
we find that a flux reduction of $\approx\!11\%$ initiates the torus
instability of the flux rope, which leads to a full eruption. These results
demonstrate that a homologous full eruption, following a confined one, can be
driven by flux cancellation.
