  Exceptional Field Theory employs an extended spacetime to make supergravity
fully covariant under the U-duality groups of M-theory. The 12-dimensional EFT
associated to the group $SL(2)\times\mathbb{R}^+$ together with its action is
presented. Demanding the closure of the algebra of local symmetries leads to a
constraint, known as the section condition, that must be imposed on all fields.
This constraint has two inequivalent solutions, one giving rise to
11-dimensional supergravity and the other leading to Type IIB supergravity and
F-theory. Thus $SL(2)\times\mathbb{R}^+$ Exceptional Field Theory contains both
F-theory and M-theory in a single 12-dimensional formalism.
