Procedure from library finvar.lib (see finvar_lib).
Usage:
invariant_basis_reynolds(REY,d[,flags]);
REY: a <matrix> representing the Reynolds operator, d: an <int>
indicating of which degree (>0) the homogeneous basis shoud be, flags:
an optional <intvec> with two entries: its first component gives the
dimension of the space (default <0 meaning unknown) and its second
component is used as the number of polynomials that should be mapped
to invariants during one call of evaluate_reynolds if the dimension of
the space is unknown or the number such that number x dimension
polynomials are mapped to invariants during one call of
evaluate_reynolds
Assume:
REY is the first return value of group_reynolds() or reynolds_molien()
and flags[1] given by partial_molien
Return:
the basis (type <ideal>) of the space of invariants of degree d
Theory:
Monomials of degree d are mapped to invariants with the Reynolds
operator. A linearly independent set is generated with the help of
minbase.