A new Physics:-Library:-SortProducts command got added to the Library, addressing the need for reordering operands in noncommutative products (Physics:-`*` and Physics:-`.`) in different ways (optional arguments of SortProducts). Note: SortProducts returns an expression mathematically equal to the input expression, just rewritten using valid operations.
An example, brief, involving annihilation and creation operators to compute the spreading of a coherent quantum state in a Fock space is attached.
The PhysicsUpdates.mw worksheet found within the PhysicsUpdates zip contains the section for SortProducts that appears in the help page for Physics,Library at Maplesoft.
This update also includes
* new `expand/%Bracket`functionality,
* various changes to handle algebra rules where one of the commutator operands is an applied Dagger.
* partially addressed "combine & Physics" functionality that was missing. For example, combine(sum_1 * sum_2) now works fine also when `*` is the noncommutative Physics:-`*` operator and when the summands in sum_1 and sum_2 are not commutative objects (example within PhysicsUpdates.mw).
* Expand now handles all the expandable Physics commands including covariant derivatives using D_, LieDerivative and Dagger.
* a couple of bug fixes involving Commutator and AntiCommutator
The update (zip file) is available for download as usual in the "Maple Physics: Research & Development" updates page.
Edgardo S. Cheb-Terrab