  For an extended locally convex space $(X,\tau)$, in [8], the authors studied
the finest locally convex topology (flc topology) $\tau_F$ on $X$ coarser than
$\tau$. One can often prove facts about $(X, \tau)$ by applying classical
locally convex space theory on $(X, \tau_F)$. This paper employs the flc
topology to analyze barreled extended locally convex spaces and establish the
uniform boundedness principle in the extended setting. One of the key results
of this paper is the relationship between the barreledness of an extended
locally convex space $(X,\tau)$ and the barreledness of the associated finest
locally convex space $(X, \tau_F)$. This is achieved by examining the lower
semi-continuous seminorms on these spaces.
