  A Siegel-type chiral p-form action is proposed in D=2(p+1) spacetime
dimensions. The approach we adopt is to realize the symmetric second-rank
Lagrange-multiplier field, introduced in Siegel's action, in terms of a
normalized multiplication of two (q+1)-form fields with q indices of each field
contracted in the even p case, or of two pairs of (q+1)-form fields with q
indices of each pair of fields contracted in the odd p case, where the
(q+1)-form fields are of external derivatives of one auxiliary q-form field for
the former, or a pair of auxiliary q-form fields for the latter. Using this
action, it is straightforward to deduce the recently constructed PST action for
q equal to zero. It is found that the Siegel-type chiral p-form action with a
fixed p (even or odd) is doubly self-dual in D=2(p+1) spacetime dimensions when
the auxiliary field(s) is/are also chosen to be of p-form. This result includes
PST's as a special case where only the chiral 0-form action is doubly self-dual
in D=2 dimensions.
