Is the combined salat different from the normal salat?

In the sunnah of the prophet, it is known that he would on occasion combine his *salawat*, especially when not doing so would cause hardship (e.g., travelling). For example, the following practice was narrated by Ibn Abbas: > The Messenger of Allah (may peace be upon him) observed the noon and afternoon prayers together, and the sunset and Isha' prayers together without being in a state of fear or in a state of journey. When this combined *salat* is performed, in what way (if any) does its form differ from the normal separated *salawat*? As in, if one were to (hypothetically) combine the dhuhr and asr *salawat*, would they... - ...pray a normal *salat* with eight *rakat*? - ...pray a normal *salat* with four *rakat*, immediately followed by another normal *salat* with four *rakat*? - ...pray a *salat* with eight *rakat*, with a *taslim* and/or *takbir* between the fourth and fifth *rakat*? - ...none of the above?