ar X iv : h ep - t h / 93 07 05 5 v 1 8 J ul 1 99 3 MZ - TH 93 - 11 Loop Integrals , R Functions and their Analytic Continuation

To entirely determine the resulting functions of one-loop integrals it is necessary to find the correct analytic continuation to all relevant kinematical regions. We argue that this continuation procedure may be performed in a general and mathematical accurate way by using the R function notation of these integrals. The twoand three-point cases are discussed explicitly in this manner. e-mail: [email protected] e-mail: [email protected] e-mail: [email protected]