  We present Atacama Large Millimeter/submillimeter Array (ALMA) observations
at 0.3 arcsec-resolution of EX Lup, the prototype of the EXor class of
outbursting pre-main sequence stars. The circumstellar disk of EX Lup is
resolved for the first time in 1.3mm continuum emission and in the $J$=2--1
spectral line of three isotopologues of CO. At the spatial resolution and
sensitivity achieved, the compact dust continuum disk shows no indications of
clumps, fragments, or asymmetries above 5-sigma level. Radiative transfer
modeling constrains the characteristic radius of the dust disk to 23 au and a
total dust mass of 1.0$\times$10$^{-4}$ M$_\odot$ (33 M_earth), similar to
other EXor sources. The $^{13}$CO and C$^{18}$O line emission trace the disk
rotation and are used to constrain the disk geometry, kinematics, and a total
gas disk mass of 5.1$\times$10$^{-4}$ M$_\odot$. The $^{12}$CO emission extends
out to a radius of 200 au and is asymmetric, with one side deviating from
Keplerian rotation. We detect blue-shifted, $^{12}$CO arc-like emission located
0.8 arcsec to the north-west, and spatially disconnected from the disk
emission. We interpret this extended structure as the brightened walls of a
cavity excavated by an outflow, which are more commonly seen in FUor sources.
Such outflows have also been seen in the borderline FU/EXor object V1647 Ori,
but not towards EXor objects. Our detection provides evidence that the outflow
phenomenon persists into the EXor phase, suggesting that FUor and EXor objects
are a continuous population in which outflow activity declines with age, with
transitional objects such as EX Lup and V1647 Ori.
