  3-dimensional Harvey Lawson submanifolds were introduced in an earlier paper
by Akbulut-Salur, as examples of Lagrangian-type manifolds inside G2 manifold.
In this paper, we first show that the space of deformations of a smooth,
compact, orientable Harvey-Lawson submanifold HL in a G2 manifold M can be
identified with the direct sum of the space of smooth functions and closed
2-forms on HL. We then introduce a new class of Lagrangian-type 4-dimensional
submanifolds inside G2, call them RS submanifolds and prove that the space of
deformations of a smooth, compact, orientable RS submanifold in a G2 manifold M
can be identified with closed 3-forms on RS.
