The PFSA program was created to do some rather large
but simple algebraic computations. PFSA does not have the large
variety of commands which more general purpose symbolic algebra
programs (muMath and Macsyma) have but it is faster and can work
with bigger expressions. PfSA ran 90 times faster than Macsyma
on a very large Hamiltonian canonical transformation project,
and it runs more than 200 times faster than muMath when doing
example E. PFSA is written in Fortran and the arithmetic involving
coefficients of terms is done with the Fortran arithmetic. Two
versions are provided, one which uses only rational integer*4
arithmetic (PFSAI.EXE) and another (PFSAF.EXE) which uses real*8
arithmetic during calculation of coefficients.

This is a program contained in the PC/Blue Library,
compiled and distributed by the New York Amateur Computer Club,
Inc, Box 3442, Church St Station, New York, NY 10008.

(modified from the documentation)