L=IPLSR(V)
[Integral polynomial list, special read. L is a list of
integral polynomials in r variables, r>=1. V is a variable list
of length r. The polynomials in L are read.
It is assumed that the list of polynomials is preceded by a left paren,
the individual polynomials are each written starting on a new line,
and the list is terminated by a right paren.]
(1) C=creadb(); if C~='(' then go to 4; L=();
(2) C=creadb(); if C==')' then go to 3;
BKSP; L1=ipsr(V); L=COMP(L1,L); go to 2.
(3) L=inv(L); return;
(4) [Error return.] print "iplsr - unexpected char";
print "empty list returned"; L=(); return..