  In this talk, we present a model based on SU(5)x(d)T which successfully gives
rise to near tri-bimaximal leptonic mixing as well as realistic CKM matrix
elements for the quarks. The Georgi-Jarlskog relations for three generations
are also obtained. Due to the (d)T transformation property of the matter
fields, the b-quark mass can be generated only when the (d)T symmetry is
broken, giving a dynamical origin for the hierarchy between m_b and m_t. There
are only nine operators allowed in the Yukawa sector up to at least mass
dimension seven due to an additional Z12 x Z12' symmetry, which also forbids,
up to some high orders, operators that lead to proton decay. The resulting
model has a total of nine parameters in the charged fermion and neutrino
sectors, and hence is very predictive. In addition to the prediction for
theta13 ~ theta_c/3sqrt{2}, the model gives rise to a sum rule,
tan^2(theta_{solar}) ~ tan^2(theta_{solar,TBM}) - 1/2*theta_c*cos(beta), which
is a consequence of the Georgi-Jarlskog relations in the quark sector. This
deviation could account for the difference between the experimental best fit
value for the solar mixing angle and the value predicted by the tri-bimaximal
mixing matrix.
