## warning (`rtable_alias`)...

Hi,

I'm trying out the 2024 version of Maple and I'm getting the following warning message:

Warning, not a built-in function (`rtable_alias`)

which I didn´t get for the 2023 version. I have no clue where it is coming from since it happens even when I start a new worksheet:

I've also attached print outs of the same worksheets (from Maple help examples and from Maple Portal), one using Maple 2023 version and the other one using Maple 2024 version so youcould see the warning and some other problems.

I really appreciate if someone would have an idea of what is going on here. Thanks very much in advance.

interpolation_2023.pdf

interpolation_2024.pdf

optimization_2023.pdf

optimization_2024.pdf

## Why does maple not add minutes to hours?...

This is perhaps a stupid question. It is quite easy to add a vector with minutes to 60 minutes. However, when I try to do this stating 1 hour instead of 60 minutes it does no longer do the calculation. Why is this? Thank you for any explanation.

QuestionMP.mw

## Command extension: Why is simplify(...,ext) not wo...

In the example below, the second call to simplify is ineffective

```eq := (a*x + b)/(c*x + d) = 1;

`simplify/nodenom`:= x -> (numer@(lhs - rhs) = 0)(x);

`simplify/nodenom`(eq);
simplify(eq, nodenom);```

Why is that?
Convert, for example, works

````convert/nodenom`:= x -> (numer@(lhs - rhs) = 0)(x);

`convert/nodenom`(eq);

convert(eq, nodenom);```

## How can I solve a set of linear differential equat...

Deal All,

I have a system of linear differential equations with unknown functions T[1](t) to T[n](t). In the attached example, I considered the value of n equal to 10, but depending on the problem, the value of n may be higher. Maple is not able to solve this problem analytically with the ‘dsolve’.

Does anyone have an idea to analytically solve for such a set of linear differential equations?

Best wishes

Set_of_Linear_DEs.mw

## Triple integral doesn't work...

I try to solve triple integraton in Maple with this code.

r := a + (b - a)*z/h;
x1 := sqrt(r^2 - y^2);
V := int(int(int(1, x = -x1 .. x1), y = -r .. r), z = 0 .. h);

but it leaves the last integral dz in the answer and warns: unable to determine if a*h/(-b+a) is between 0 and h; try to use assumptions or use the AllSolutions option
What is the problem?
and i need to get V = Pi*h(a^2 + ab +b^2)/3

Regards

## Maple solve hangs depending on what letters are us...

Could someone help me understand why Maple hangs solving these two equations when the names of unknowns is c__1,c__2   or the old _C1, _C2?

This worksheets shows this. I had to put timelimit of 90 seconds, else it hangs may be forever.

This example came from looking at why Maple seems to hang randomly when I run the same problem. I still do not know why, but is seems to have something to do with the use of  lower case c__1 or _C1.

 > interface(version);

 > Physics:-Version();

 > restart;
 > dsolve(diff(y(x),x\$9)=1,arbitraryconstants=subscripted);

 > eqs:=[-1/2*arctanh(1/2*sqrt(1 + 2*c__1)*sqrt(2)/sqrt(c__1))*sqrt(2)/sqrt(c__1) = c__2, 1 = (-exp(2*c__2*sqrt(c__1)*sqrt(2)) + 1)*sqrt(c__1)*sqrt(2)/(exp(2*c__2*sqrt(c__1)*sqrt(2)) + 1)]; unknowns:=[c__1,c__2]; time(); C_sol:=[timelimit(90,solve(eqs,unknowns))]; time()

Error, (in evalf/hypergeom) time expired

 > restart; #try again but do not do the arbitraryconstants=subscripted now.
 > eqs:=[-1/2*arctanh(1/2*sqrt(1 + 2*c__1)*sqrt(2)/sqrt(c__1))*sqrt(2)/sqrt(c__1) = c__2, 1 = (-exp(2*c__2*sqrt(c__1)*sqrt(2)) + 1)*sqrt(c__1)*sqrt(2)/(exp(2*c__2*sqrt(c__1)*sqrt(2)) + 1)]; unknowns:=[c__1,c__2]; time(); C_sol:=[timelimit(90,solve(eqs,unknowns))]; time()

 > #see? it finisghed instantly now.

The same thing happens If I use the old _C1 and _C2 instead of c__1 and c__2. It also hangs.

The following worksheet shows this.  If I change _C1 and _C2 to other symbols, say C1 and C2, then it does not hang.

Why the names of the unknowns makes difference to solve?

 > restart;

 > eqs:=[-1/2*arctanh(1/2*sqrt(1 + 2*_C1)*sqrt(2)/sqrt(_C1))*sqrt(2)/sqrt(_C1) = _C2, 1 = (-exp(2*_C2*sqrt(_C1)*sqrt(2)) + 1)*sqrt(_C1)*sqrt(2)/(exp(2*_C2*sqrt(_C1)*sqrt(2)) + 1)]; unknowns:=[_C1,_C2]; time(); C_sol:=[timelimit(90,solve(eqs,unknowns))]; time()

Error, (in evalf/cos) time expired

 > restart;

 > eqs:=[-1/2*arctanh(1/2*sqrt(1 + 2*C1)*sqrt(2)/sqrt(C1))*sqrt(2)/sqrt(C1) = C2, 1 = (-exp(2*C2*sqrt(C1)*sqrt(2)) + 1)*sqrt(C1)*sqrt(2)/(exp(2*C2*sqrt(C1)*sqrt(2)) + 1)]; unknowns:=[C1,C2]; time(); C_sol:=[timelimit(90,solve(eqs,unknowns))]; time()

Only thing I see in help related to name of symbols to solve for is this:

The solve command solves one or more equations or inequalities for the specified unknowns. The unknowns may be names, including indexed names (though for efficiency reasons, indexed names should be avoided when possible),

ps. This looks like a bug to me. So I send bug report to Maplesoft support also.

pps. I tried this in Maple 2023 and Maple 2022 and same behavior. Could someone with earlier version of Maple try to see if this behavior was there also?   It can possibly be correct that the choice of letter used makes difference for solving equations. I have to use c__1 and c__2 etc.. since these equations come from differential equations and this is what I use for constants of integrations., Otherwise I have to make lots of changes now to use different letters.

Update

did trace on solve using _C1 and _C2 and then using A,B for variables to solve for. Code flow is different. This expalins why it hangs. The flow starts the same until it gets to

TriangularDecomposition: something went wrong during backsubstitution - trying a different variable order

Then when using _C1 and _C2 the code goes into different path than when using A,B.

Here is flow when using _C1,_C2.

```eqs:=[-1/2*arctanh(1/2*sqrt(1 + 2*_C1)*sqrt(2)/sqrt(_C1))*sqrt(2)/sqrt(_C1) = _C2, 1 = (-exp(2*_C2*sqrt(_C1)*sqrt(2)) + 1)*sqrt(_C1)*sqrt(2)/(exp(2*_C2*sqrt(_C1)*sqrt(2)) + 1)];
unknowns:={_C1,_C2};
time();
infolevel[solve]:=5;
C_sol:=[timelimit(60,solve(eqs,unknowns))];
time()

Main: Entering solver with 2 equations in 2 variables
Main: attempting to solve as a linear system
Recurse: recursively solving 2 equations and 2 inequations in 2 variables
Transformer:   solving for linear equation in _X000001
Recurse: recursively solving 2 equations and 2 inequations in 2 variables
Recurse: recursively solving 3 equations and 2 inequations in 3 variables
Dispatch: dispatching to Exponentials handler
Transformer:   solving for linear equation in _S000004
Recurse: recursively solving 3 equations and 3 inequations in 4 variables
Dispatch: dispatching to Rename handler
Dispatch: renaming _S000005 = arctanh(1/2*_S000002*RootOf(_Z^2-2,index = 1)/_S000001)
Recurse: recursively solving 3 equations and 3 inequations in 5 variables
Dispatch: handling polynomials of the form a*x^n-b
Dispatch: dispatching to PolynomialSystem handler
Main: polynomial system split into 1 parts under preprocessing
Main: using RegularChains based methods
SolverVariableOrder: using the variable order  _S000003 > _X000002 > _S000005 > _S000002 > _S000001
TriangularDecomposition: using deterministic algorithm for decomposition
TriangularDecomposition: decomposition successfully found 1 components
TriangularDecomposition: backsubstituting to form solutions
TriangularDecomposition: something went wrong during backsubstitution - trying a different variable order
Transformer:   solving the uncoupled linear subsystem in {_S000003, _X000002}
Linear: solving 2 linear equations
Polynomial: # of equations is: 2
Polynomial: best equation / unknown _S000005*_z1 _X000002 2*_S000001
Polynomial: # of equations is: 1
Polynomial: best equation / unknown -_z1*_S000001+1 _S000003 _z1*_S000001+1
Polynomial: backsubstitution at: 2
Polynomial: backsubstitution at: 1
Main: polynomial system split into 1 parts under preprocessing
Main: subsystem is essentially univariate
UnivariateHandler: subsystem has only one equation
UnivariateHandler: solving as if univariate in _S000002
Recurse: recursively solving 1 equations and 0 inequations in 1 variables
Dispatch: dispatching to OnlyIn handler
Transformer:   solving for linear equation in _S000006
Recurse: recursively solving 1 equations and 0 inequations in 1 variables
Transformer:   solving the uncoupled linear subsystem in _S000006
Recurse: recursively solving 1 equations and 1 inequations in 1 variables
Transformer:   solving the uncoupled linear subsystem in t
Error, (in evalf/hypergeom) time expired
```

This is trace when using A,B

```eqs:=[-1/2*arctanh(1/2*sqrt(1 + 2*A)*sqrt(2)/sqrt(A))*sqrt(2)/sqrt(A) =B, 1 = (-exp(2*B*sqrt(A)*sqrt(2)) + 1)*sqrt(A)*sqrt(2)/(exp(2*B*sqrt(A)*sqrt(2)) + 1)];
unknowns:={A,B};
time();
infolevel[solve]:=5;
C_sol:=[timelimit(90,solve(eqs,unknowns))];
time()

Main: Entering solver with 2 equations in 2 variables
Main: attempting to solve as a linear system
Recurse: recursively solving 2 equations and 2 inequations in 2 variables
Transformer:   solving for linear equation in A
Recurse: recursively solving 2 equations and 2 inequations in 2 variables
Recurse: recursively solving 3 equations and 2 inequations in 3 variables
Dispatch: dispatching to Exponentials handler
Transformer:   solving for linear equation in _S000004
Recurse: recursively solving 3 equations and 3 inequations in 4 variables
Dispatch: dispatching to Rename handler
Dispatch: renaming _S000005 = arctanh(1/2*_S000002*RootOf(_Z^2-2,index = 1)/_S000001)
Recurse: recursively solving 3 equations and 3 inequations in 5 variables
Dispatch: handling polynomials of the form a*x^n-b
Dispatch: dispatching to PolynomialSystem handler
Main: polynomial system split into 1 parts under preprocessing
Main: using RegularChains based methods
SolverVariableOrder: using the variable order  _S000003 > B > _S000005 > _S000002 > _S000001
TriangularDecomposition: using deterministic algorithm for decomposition
TriangularDecomposition: decomposition successfully found 1 components
TriangularDecomposition: backsubstituting to form solutions
TriangularDecomposition: something went wrong during backsubstitution - trying a different variable order
Main: polynomial system split into 1 parts under preprocessing
Main: applying the solver for domain=absolute, engine=traditional
PseudoResultant: 225530 [1 200002087 _S000001] 3 3 151 2 45 0
PseudoResultant: 120059 [2 200004772 _S000003] 2 2 131 0 3 0
PseudoResultant: 134507 [1 700002396 _S000002] 1 1 53 0 3 0
PseudoResultant: -10 [] 0 0 3 0 3 0
PseudoResultant: 1 solutions found, now doing backsubstitution
PseudoResultant: backsubstitution of _S000002
PseudoResultant: backsubstitution of _S000003
PseudoResultant: backsubstitution of _S000001
SolutionsLost: setting solutions lost flag
Main: solving successful - now forming solutions
Main: Exiting solver returning 0 solutions

solve: Warning: no solutions found```