In fact all that is needed is one section running along the real time axis as the route to the end point, t i − i β {\displaystyle t_{i}-i\beta } , is less important.
事實上，真正需要的是一段經過實數軸的路段，而前往終點 t i − i β {\displaystyle t_{i}-i\beta } 所選的路線是較不重要的。