492 BELL SYSTEM TECHNICAL JOURNAL 



There are now available a number of methods of evaluating opera- 

 tional forms, among which may be mentioned 



The original Heaviside expansion theorem, 

 Operational Division which gives a series solution, 

 Contour Integration of the Bromwich-Fourier Integral, 

 Carson's Integral Equation. 



It is thought that this extension to the expansion theorem will be of 

 value as another way of evaluating in closed form certain operational 

 expressions, especially those involving fractional exponents. 



In preparing this paper, the author wishes to acknowledge his 

 indebtedness to Mr. R. M. Foster for the contribution of Equivalent 

 No. 7 in its present form and for notes regarding the evaluation of the 

 error function. He is also indebted to Mr. J. R. Carson for reading a 

 draft of the manuscript and for a number of helpful suggestions. 



