Editing Contour integration (section)

====Contour note====
As an aside, a question can arise whether we do not take the semicircle to include the ''other'' singularity, enclosing {{math|−''i''}}. To have the integral along the real axis moving in the correct direction, the contour must travel clockwise, i.e., in a negative direction, reversing the sign of the integral overall.

This does not affect the use of the method of residues by series.