Function: intmellininv
Section: sums
C-Name: intmellininv0
Prototype: V=GGEDGp
Help: intmellininv(X=sig,x,s,{tab}): numerical integration on the 
 line real(z) = sig (or sig[1]) of s(z)x^(-z)dz/(2*I*Pi), i.e. inverse Mellin 
 transform of s at x. sig is coded as follows: either it is real, and then
 by default assume s(z) decreases like exp(-z). Or sig = [sigR, al], sigR is
 the abcissa of integration, and al = 0 for slowly decreasing functions, or
 al > 0 if s(z) decreases like exp(-al*z). tab is as in intnum. Use 
 intmellininvshort if several values must be computed.

