Here is the minimal working example: 

with(Physics):
Setup(noncommutativeprefix={W,V});
simplify(W^(-1)*(-W^(-1)-W*V^(-2)));

It gives the result  below, which is wrong. Or am I misinterpreting? (Maple 2018)

(-V^2-W^2)*(1/V^2)*(1/W^2)

Hello,

in Maple 2017 (could not try 2018) the following is a bug;
 

with(LinearAlgebra);
U:= Matrix(4,4, shape=triangular[upper, unit], symbol =u);
-U;

It returns the wrong matrix, with +1 on the diagonal and -u_{ij} on the upper part. That is, it changes the sign only of the entries in the upper part. The bug is for any size, and also for lower triangular.

 

Hello,

it seems that Maple2017 handles the noncommutative product wrongly (while it used to do it properly up to maple 17 afaik). 

CODE:

with(Physics);
Setup(noncommutativeprefix={P,Q});
Q^2*P*Q + Q*P*Q^2;
simplify(%);

gives a correct result: BUT 

Q(t)^2*P(t)*Q(t) + Q(t)*P(t)*Q(t)^2;
simplify(%)

gives the result:

2Q(t)^3*P(t)  (which is wrong).

It used to work fine in Maple 17. I need to differentiate noncommutative polynomials in P(t), Q(t), which was done without problem in Maple 17 but now seems to be broken. 

Any explanation/workaround/fix? Is it fixed in Maple 2018?