  We prove that a (lax) bilimit of a 2-functor is characterized by the
existence of a limiting contraction in the 2-category of (lax) cones over the
diagram. We also investigate the notion of bifinal object and prove that a
(lax) bilimit is a limiting bifinal object in the category of cones. Everything
is developed in the context of marked 2-categories, so that the machinery can
be applied to different levels of laxity, including pseudo-limits.

Category Theory;Algebraic Topology