Neidhardt H., Zagrebnov V.A.
On Error Estimates for the Trotter-Kato Product Formula.
(42K, LATeX 209)

ABSTRACT.  We study the error bound in the operator-norm topology for the
Trotter exponential product formula as well as for its 
generalization a la Kato. In the frame of the abstract setting
we give a simple proof of error estimates which improve some 
recent results in this direction.