"Reduced Exponential" I am interested in what I call the "reduced exponential" Sum_i=1 to infinity x^(i-1) / i! where x is a general element in an algebra of interest. Only when x is invertible is the reduced exponential equivalent to (exp(x)-1) /x . Obviously we have a "reduced log", the inverse of the reduced exponential. Does anybody of any work or formulae involving this construct? TIA.