Hello, I have a question about a complex integral. The question is about the index of a curve. This curve is defined as: j = j1 * j2 with j1: r*exp(i*t) with t: [0,pi] and j2: [-r,r] This is quite simple: a half cirle followed by a line from (-r,0) through (0,0) to (r,0). To calculate the index Ind(a) over the curve j: Ind(a) = 1/(2*pi*i) * integral(dz/(z-a)) Now the problem: I used a curve (a+r*exp(it)) to solve the half circle, this give me 1/2. But how can I calculate the index of the line from (-r,0) to (r,0)?