  We develop a new definition of opetopic sets. There are two main technical
ingredients. The first is the systematic use of fibrations, which are implicit
in most of the approaches in the literature. Their explicit use leads to
certain clarifications in the construction of opetopic sets and other
constructions. The second is the "web monoid", which plays a role analogous to
the "operad for operads" of Baez and Dolan, the "multicategory of function
replacement" of Hermida, Makkai and Power. We demonstrate that the web monoid
is closely related to the "Baez-Dolan slice construction" as defined by Kock,
Joyal, Batanin and Mascari.
