I can't figure what is going on here. I have an expression, where when I run the program, I see inside the debugger that the result of **evalb(simplify(tmp_1)) **where tmp_1 is the expression, gives **false**

When I copy the same tmp_1 expression to new worksheet and do **evalb(simplify(tmp_1)) **it gives **true.**

I added print statements in the code to print **tmp_1** and print result of **simplify(tmp_1) **and for some reason, it gives false when I run the program, but it gives true when I do the same thing in a work sheet, by copying **tmp_1 **and trying it there.

Never seen anything like this, as expression is all numbers. Here is the print out when I run the program

Here is the same thing in worksheet

restart;
tmp_1 :=-(2*ln(-2))/7 - ln(-1)/7 = ln(1) - (2*ln(-2))/7 - ln(-1)/7;
simplify(tmp_1);
evalb(simplify(tmp_1));

**true**

and if you think I made mistake somewhere, here is also screen shot from the debugger window itself

again, same thing gives true in separate worksheet, copying same exact expression from above

There seem to be something loaded when I run my program that causes this difference, but I have no idea now what it is. This has nothing to do with the debugger loaded btw, I am just using the debugger to show the details. When I run the program, without the debugger, I get false for the above, and I was trying to find why.

Any suggestions what to try and what to check for and what could cause this? Should it not give true when I run the program also? Could it be some Digits setting changed when the program run? I do not change any system defaults of any sort when running the program.

Maple 2020.1

**edit june 12, 2021**

Here is another manifestation of the same problem I just found. There is something seriously wrong for it to behave this way.

This is an expression called **tmp_1** in a local variable in a proc inside a module. There are not even any local symbols in it. When I run the program, all the attempts to show it is true fail. Some give **FAIL** and some give **false** when the result should be **true**

When I simply copy the expression from the debugger window to an open worksheet, I get **true**

Here is the screen shot

Only when I did **is(expand(tmp_1))** did it give true

But when I copy the expression to the worksheet, it gives true using all the other attempts:

restart;
tmp_1:=1 = 5/4*exp(0)+1/4*piecewise(0 <= 1,-1,1 < 0,exp(-2)):
is(tmp_1);
is(simplify(tmp_1));
is((rhs-lhs)(tmp_1)=0);
is(simplify((rhs-lhs)(tmp_1)=0));
evalb(simplify((rhs-lhs)(tmp_1)=0));
is(expand(tmp_1))

I can't make a MWE so far, since these problems only show up with I run my large program. I think Maple internal memory get messed up or something else is loaded that causes these stranges problems.

For now, I added **expand() **to the things I should try. My current code now looks like

if is(tmp_1) or is(simplify(tmp_1)) or is((rhs-lhs)(tmp_1)=0)
or is(simplify((rhs-lhs)(tmp_1)=0)) or evalb(simplify((rhs-lhs)(tmp_1)=0))
or is(expand(tmp_1)) then
....

Maple 2021.1