I can't understand this behavior. Any idea why it happens?

Solve is able to solve equation   f(y)=x+A for y, but can't solve   f(y)=x for y.

This is unexpected for me. I do not see why it can solve it when RHS is x+A but not when RHS is just x.

I can trick it to solve  f(y)=x for y  by asking it to solve f(y)=x+A for y and then set A=0 in the solution. But one should not have to do this. Is this a bug or Am I missing something?

Download why_solve_when_adding_term_only_may_22_2024.mw

Why Maple gives this error on solving first order linear ode using ODESteps? 

Download odesteps_fail_may_10_2024.mw

ps. also reported to Maplesoft customer support.

I never used Maple's StringTools:-RegSubs before.

I have a Latex string generated by Maple that has this form

"......    \\textrm{ ......   }  .... "

Where the dots mean anything, including space characters.  I need to change the part of the string  "\\textrm{ ...... }" to this

"......  \\begin{minipage}{\\linewidth}\\textrm{  ......   }\\end{minipage}  .... "

It is easy to change the opening part. Here is an example

s:="A& B& \\textrm{The fundamental matrix has } &C ";
s:=StringTools:-SubstituteAll(s,"\\textrm{","\\begin{minipage}{\\linewidth}\\textrm{");

Gives

The problem is how to replace the closing "}"  with "}\\end{minipage}".   I can't just replace "}" with "}\\end{minipage}" using SubstituteAll because I need to only change the "}" that closes the corresponding "\\textrm{" and not any other "}" that could be in the string.

So I need to use pattern matching or regular expression substitutions. The examples in help are not easy to understand.

Basically I need regular expression that matches 

                        "\\textrm{ WILDCARD * }" 

and change it to 

                        "\\begin{minipage}{\\linewidth}\\textrm{ WILDCARD * }\\end{minipage}" 

Any one know how to use Maple's egular expression to do this substitution using the above example?

Maple 2024 on windows 10.

Update

Thanks for the replies. I ended up writing small function that simply scan the string and do the replacement. 

I was attempting to remove part of string using StringTools:-Remove()

But it causes server.exe crash each time.

Any idea why this happens?

Worksheet below

Download crash_during_string_tools_remove_maple_2024.mw

ps. reported to Maplesoft also.

Maple dsolve fails to find many singular solutions using the option 'singsol'=all.

Any idea why that is? Here is one example

ode:=diff(y(x),x)=(y(x)-3)^2;
dsolve(ode,y(x),'singsol'=all)

It returns 

But we see that y=3 is singular solution which can't be obtained from the above solution for any value of c1

Mathematica finds this singular solution

ode=y'[x]==(y[x]-3)^2
DSolve[ode,y[x],x,IncludeSingularSolutions->True]

Here is second example.

restart;
ode:=diff(y(x),x)=2*x*sqrt(1-y(x)^2);
dsolve(ode,y(x),'singsol'=all)

Gives

But it misses the y=1,y=-1 singular solutions. 

Is there something I am doing wrong? Why does Maple sometimes fail to find singular solutions?

ps. reported to Mapesoft also.

Update

I remembered now a case similar to this. one has to use `Lie` solver and now Maple gives the singular solution

ode:=diff(y(x),x)=(y(x)-3)^2;
dsolve(ode,Lie,'singsol'=all)

There is no mention of this in help and it is still not clear to me if one has to always use Lie solver to obtain singsol or if this is just a coincidence for this one case.  

Same for the other case:

restart;
ode:=diff(y(x),x)=2*x*sqrt(1-y(x)^2);
dsolve(ode,'Lie','singsol'=all)

gives

I think singsol should work all the time and not only when using specific solver. If Lie solver is needed for singsol to work, then help should be clear and say this.