The paper discusses the current state of neutrino oscillation data and the concept of tri-bimaximal mixing. Recent results from the SNO and K2K experiments suggest that neutrino mixing is characterized by effective bimaximal mixing of νμ and ντ at the atmospheric scale and effective tri-maximal mixing for νe with νμ and ντ at the solar scale, leading to the term 'tri-bimaximal' mixing. The authors present simple mass matrices that lead to this mixing pattern and discuss its relation to the Fritzsch-Xing democratic ansatz. The solar data, including recent SNO measurements, indicate a suppression of νe flux of approximately 1/3, consistent with tri-bimaximal mixing. The atmospheric neutrino data suggest twofold maximal mixing of νμ and ντ, with the survival probability of νμ being around 0.5. The K2K experiment supports a mass-squared difference of approximately 3×10⁻³ eV², which is consistent with the atmospheric neutrino data and inconsistent with the original trimaximal model. The authors propose a lepton mixing matrix based on tri-bimaximal mixing, which is closely related to the Fritzsch-Xing democratic ansatz. They present mass matrices that lead to this mixing pattern and show that the resulting mixing matrix is consistent with the current data. The tri-bimaximal mixing model predicts specific survival probabilities for neutrinos, which are consistent with the experimental data. However, the model does not account for CP violation or high-energy matter resonance, which might be considered a limitation. The paper concludes that tri-bimaximal mixing is a viable model that explains the current neutrino oscillation data, and that future experiments will help to confirm or refine this model. The authors also note that the Fritzsch-Xing ansatz is now essentially ruled out, and that many other schemes involving energy-independent solar solutions are also inconsistent with the SNO results.The paper discusses the current state of neutrino oscillation data and the concept of tri-bimaximal mixing. Recent results from the SNO and K2K experiments suggest that neutrino mixing is characterized by effective bimaximal mixing of νμ and ντ at the atmospheric scale and effective tri-maximal mixing for νe with νμ and ντ at the solar scale, leading to the term 'tri-bimaximal' mixing. The authors present simple mass matrices that lead to this mixing pattern and discuss its relation to the Fritzsch-Xing democratic ansatz. The solar data, including recent SNO measurements, indicate a suppression of νe flux of approximately 1/3, consistent with tri-bimaximal mixing. The atmospheric neutrino data suggest twofold maximal mixing of νμ and ντ, with the survival probability of νμ being around 0.5. The K2K experiment supports a mass-squared difference of approximately 3×10⁻³ eV², which is consistent with the atmospheric neutrino data and inconsistent with the original trimaximal model. The authors propose a lepton mixing matrix based on tri-bimaximal mixing, which is closely related to the Fritzsch-Xing democratic ansatz. They present mass matrices that lead to this mixing pattern and show that the resulting mixing matrix is consistent with the current data. The tri-bimaximal mixing model predicts specific survival probabilities for neutrinos, which are consistent with the experimental data. However, the model does not account for CP violation or high-energy matter resonance, which might be considered a limitation. The paper concludes that tri-bimaximal mixing is a viable model that explains the current neutrino oscillation data, and that future experiments will help to confirm or refine this model. The authors also note that the Fritzsch-Xing ansatz is now essentially ruled out, and that many other schemes involving energy-independent solar solutions are also inconsistent with the SNO results.