  The homotopy theory of infinity-operads is defined by extending Joyal's
homotopy theory of infinity-categories to the category of dendroidal sets. We
prove that the category of dendroidal sets is endowed with a model category
structure whose fibrant objects are the infinity-operads (i.e. dendroidal inner
Kan complexes). This extends the theory of infinity-categories in the sense
that the Joyal model category structure on simplicial sets whose fibrant
objects are the infinity-categories is recovered from the model category
structure on dendroidal sets by simply slicing over the point.
