Bug?: (a^b).unit(a) -> SIGSEGV

Hi, Notice that (a^b).unit(a) leads to Segmentation fault. I have failed to track down the source of this fault in GiNaC --- I would expect that this expression should throw an exception "invalid expression in unit()", but something gets wrong elsewhere. Any ideas? Pearu For your convinience, here is a sample program: #include <iostream> #include <ginac/ginac.h> using namespace std; using namespace GiNaC; int main() { symbol a("a"),b("b"); ex e = power(a,b); cout << "e="<<e<< endl; cout << "e.unit(a)="<<e.unit(a)<< endl; return 0; }