Multivalued Inverse Functions: mathematical treatment and
implementation in computer algebra systems.
David Jeffrey
Department of Applied Mathematics, University of
Western
Ontario, London, Canada
Monday, February 10, 2003 13:0014:00, Room 145, NIST North (820) Gaithersburg Monday, February 10, 2003 11:0012:00, Room 4511 Boulder
Abstract:
The implementation of elementary functions, such as
logarithm
and the inverse trigonometric functions, in computer algebra
systems has
shown that we need to think about multivalued functions carefully.
In
this talk, I explain the requirements of a computer algebra system
and
review the possible definitions of a multivalued function. I
compare
multiple values (sets of values), Riemann surfaces and principal
values. For CAS, principal values is best, but that requires
rethinking
the simplification rules.
How we are doing this is described.
Contact: D. W. LozierNote: Visitors from outside NIST must contact
Robin Bickel; (301) 9753668;
at least 24 hours in advance.
