India today said it would ‘‘certainly’’ look into Pakistan President Pervez Musharraf’s recent formulation to resolve the Kashmir issue if it is made formally but firmly ruled out third party mediation.‘‘If such a formal proposal is made, we will certainly look into it,’’ External Affairs Minister K. Natwar Singh said when asked about Musharraf’s proposal that India and Pakistan should identify ‘‘regions’’ of Kashmir on both sides of the LoC, demilitarise them and grant them the status of independence or joint control or under UN mandate.Singh said India would hold ‘‘substantial’’ talks with Pak PM Shaukat Aziz during his three-day visit to New Delhi from November 23. ‘‘We are looking forward to the visit of Aziz,’’ Singh told reporters on board IAF aircraft while returning from Cairo after attending the military funeral of Palestinian leader Yasser Arafat.‘‘It is obvious that we will also have substantial talks with him,’’ he said.‘‘As far as we are concerned, this (Kashmir) is a bilateral matter. A third party involvement will not be acceptable to India,’’ he said when asked about Richard Armitage’s comments describing Musharraf’s suggestion as ‘‘very forward-looking’’.