Thank you all for your ideas. I would be happy if Maple had a robust command specifically for this purpose. I need this functionality regularly.

@eithne 

Thanks for the patch, but the Maple update itself didn't solve the problem, I needed to install Visual C++ Redistributable for Visual Studio 2012 Update 4.

If you are interested in using a numerical circuit simulator I recommend Micro-Cap, which is free from last year. It has a large component library.

http://www.spectrum-soft.com/index.shtm

@vv Thanks for the idea. I 'll try it.

@acer Thanks for submitting bug report.

@acer  I get the following error  message:

e := (a or b) and (not a or not b) and (a or not b);
SMTLIB:-Satisfiable(e);

Error, (in SMTLIB:-Satisfiable) external linking: error loading external library mplsmtlib.dll:....

@tomleslie Other difference between the different windows, that I use a non-English language Windows, but I don't know whether it counts here.

@djc

I have executed the problematic command with setting printlevel to 500.

I attached the output:

printlevelforis.mw

@tomleslie 

Thank you all for the feedbacks.

My version info:

restart;
kernelopts(version);
is(0 <= (a - b)^2 + (c - d)^2) assuming real;
is(x = 0) assuming (0 < abs(x));
   Maple 2020.0, X86 64 WINDOWS, Mar 4 2020, Build ID 1455132

                              FAIL

                              FAIL

@acer I have 64 bit windows 10 Enterprise.

I wish Maple 2019 can compute the probability of a conditional event symbolically with several, correlated random variables. Also, I would like to compute the conditional expected value with Maple.

So, I would like to see a similar functionality in Maple as in Mathematica:

https://reference.wolfram.com/language/ref/Conditioned.html

@Markiyan Hirnyk Thanks for pointing out the more general solution and for voting up.

I suggest a little modification, because there is a possible rounding problem with the last digit of S.
S contains the first n digits of Pi :

S := convert(evalf[n+1](Pi), string)[..n+1];

I suggest a little modification, because there is a possible rounding problem with the last digit of S.
S contains the first n digits of Pi :

S := convert(evalf[n+1](Pi), string)[..n+1];

See also the help-page ?do 

"If the end do is terminated by a colon instead of a semicolon, display of all results (but not explicit output) from within the loop are suppressed, ..."