Ticket #3372 (closed defect: fixed)

Opened 4 months ago

Last modified 2 months ago

expand on (x+y)^n fails for non-commutative (x,y) [new symbolics]

Reported by: cwitty Assigned to: gfurnish
Priority: major Milestone:
Component: symbolics Keywords:
Cc:

Description 

sage: var('x,y', MatrixSpace(QQ, 5, 5))
(x, y)
sage: ((x+y)^3).expand()
x^3 + x*y*x + y*x*x + x*y^2 + y*x^2 + x*y*y + y*x*y + y^3

This is the wrong answer (it has two terms x*y*y and x*y^2, when only one should exist; and it does not have an x^2*y); also, this answer is printed poorly (x*y*y + ... + x*y^2 should simplify to 2*x*y^2 + ...).

Change History

07/18/2008 03:39:27 AM changed by gfurnish

  • status changed from new to closed.
  • resolution set to fixed.

Fixed in sage-symbolics commit 10238. This was caused by an out of order list reordering while creating a symbolic product.

08/23/2008 01:14:14 AM changed by was

  • milestone deleted.

Milestone sage-symbolics deleted