I want to determine components of a vector in explicit form.  Let I have vector nn[mu] with components (1,0,0,0). Is it possible to explain to Maple it?

I tried to do the next:

The answer that maple gives is:

So, doesn't Maple understand that nn[1]=nn[2]=nn[3]=0?

Hi, there!

I try to simplify the next expression:

Simplify(LeviCivita[4, sigma, lambda, rho]*LeviCivita[4, xi, eta, mu]*g_[rho, mu]*qp[sigma]*q[lambda]*qp[xi]*q[eta])

Maple gives the answer:

In reality, it is the incorrect answer, because indices must run over 1,2,3 but not 1,2,3,4!

SumOverRepeatedIndices(%) confirms that maple mistakes.

my preamble is:

with(Physics)

Setup(mathematicalnotation = true);
Coordinates(X);

Setup(spaceindices = lowercaselatin)

Setup(tensors = q[mu](X))

PDEtools:-declare(q(X))

Setup(tensors = qp[mu](X))

PDEtools:-declare(qp(X))

Hi, there!

I try to simplify the next expression:

Simplify(LeviCivita[4, sigma, lambda, rho]*LeviCivita[4, xi, eta, mu]*g_[rho, mu]*qp[sigma]*q[lambda]*qp[xi]*q[eta])

Maple gives answer:

In reality it is incorrect answer, because indices must run over 1,2,3 but not 1,2,3,4!

SumOverRepeatedIndices(%) confirms that maple mistakes.

my preamble is:

with(Physics)

Setup(mathematicalnotation = true);
Coordinates(X);

Setup(spaceindices = lowercaselatin)

Setup(tensors = q[mu](X))

PDEtools:-declare(q(X))

Setup(tensors = qp[mu](X))

PDEtools:-declare(qp(X))

Hi.  I've spent the last 5 hours or so working on a worksheet on Maple, without saving but with autosaving every 15 min. 

Maple worksheet crashed. When I opened it again, that all changes were losted! But I find autosave .bak  file. How may I open it?

Is there any way I can recover my work?

Hello everyone, I use physics package and I input:

with(Physics)

Setup(mathematicalnotation = true)

Coordinates(X)

Setup(tensors = A[mu](X))

PDEtools:-declare(A(X))

PDEtools:-declare(p0(X), pm(X), pp(X), pt(X), Un(X), Ucn(X))

pt := proc (X) options operator, arrow; Matrix(2, 2, [[p0(X), sqrt(2)*pp(X)], [sqrt(2)*pm(X), -p0(X)]]) end proc

U := proc (X) options operator, arrow; Matrix(2, 2, [[1, 0], [0, 1]])+I*pt(X)*(1/f)-pt(X)*pt(X)*((1/2)/f^2) end proc

Ucn := proc (X) options operator, arrow; Matrix(2, 2, [[1, 0], [0, 1]])-I*pt(X)*(1/f)-pt(X) . pt(X)*((1/2)/f^2) end proc

And after that I write:

Trace(-LeviCivita[mu, nu, rho, sigma] . Ucn(X) . ((1/6)*e*A[nu](X)+M5*KroneckerDelta[nu, 0]) . Matrix(2, 2, [[1, 0], [0, 1]]) . Uсn(X) . d_[rho](Un(X)) . Uсn(X) . d_[sigma](Un(X)))

But I get an error:

Error, (in unknown) invalid subscript selector

Thanks for the help.