What is the ruling on the shortened prayer (Salat al-Qasr) for a traveler of four years, and what is the opinion of the two Sheikhs, Ibn 'Uthaymeen and Ibn Baz, on this?

A traveler must complete the prayer if he intends to stay four days or more. This is the view of Malik and Al-Shafi'i, in contrast to Imam Ahmad, who holds that the prayer must be completed if one intends to stay for more than four days.