// global functions
-inline symmetry &ex_to_nonconst_symmetry(const ex &e)
-{
- return static_cast<symmetry &>(*e.bp);
-}
inline symmetry sy_none(void) { return symmetry(); }
inline symmetry sy_none(const symmetry &c1, const symmetry &c2) { return symmetry(symmetry::none, c1, c2); }