A function
is piecewise continuous on a closed interval
if there is a finite partition
such that
is continuous on every open
subinterval
and has a finite limit
from within each adjacent open subinterval at its endpoints. The value of
at a partition point need not equal either one-sided limit,
so the possible discontinuities are removable
discontinuities and jump discontinuities.
The definition extends to other intervals by requiring piecewise continuity on every closed bounded subinterval.