I noticed Maple gives different order of term (but still correct) when variable y or z is used, vs. other letters in this computation.

In this example below, integral results are given, using one letter of the alphabet at a time in the integrand. 

Only when the variable is y or z, Maple shows expression in different form from all the others (negative sign pulled out). The result are correct ofcourse, but was wondering why this hapens only for these two variables? I would have expected that variable name (letter used) should not make any difference to the final form.

restart;
interface(rtablesize=infinity):
chars:=[seq(parse(StringTools:-Char(i)),i=97..122)]: #generate a..z variables, may be there is better way?
Matrix([seq([chars[i0],simplify(int((c0^2 - c1^2)/(chars[i0] - x0+I*c3), x0))],i0=1..nops(chars))]);

Gives (this below. Notice the very last 2 entries below)

Is this something common in Maple? Does it depend on the computation being performed? Can a user do something to tell Maple not to change order/form of expression depending on what variable letter is used?

Give this

ode:=diff(y(x),x)=a*cos(y(x))+b;
sol_1:=2*arctan( (a+b)/sqrt(b^2-a^2) * tan(1/2*sqrt(b^2-a^2)*(x+_C1)));
sol_2:=2*arctan( sqrt(a+b)/sqrt(b-a) * tan(1/2*sqrt(b^2-a^2)*(x+_C1)));

sol_1 and sol_2 are the same. Only difference is that I wrote  (a+b)/sqrt(b^2-a^2) in one, and  sqrt(a+b)/sqrt(b-a) in the other. But these two expressions are the same. But odetest gives zero on the first and not on the second:

odetest(y(x)=sol_1,ode);
       0

odetest(y(x)=sol_2,ode);
       not zero 

Why did Maple not verify sol_2?

Maple 2016.1 on windows 7

Maple debugger uses very small font, different from main worksheet. It seems to use its own font size. Changing font size on the main worksheet has no effect.

For example, if you type

restart;
f:=proc()
return 3;
end proc;

stopat(f);

f();

Now the debugger comes up. On my system, windows 7, and Maple 2016, the font is very small. I'd like to make it larger.

How can one do this? I looked at format->style but see nothing related to debugger.

when writing by error the following

restart;
f:=proc()
dsolve(diff(y(x),x)+y(x)=0,y(x));
end proc();

Maple did not complain and returned  f := y(x) = _C1*exp(-x)

Then I noticed I needed to change "end proc();" to "end proc;" 

The question is, why did Maple not generate a syntax error? If "end proc();" is valid Maple code, then what does it mean? or Did Maple ignore it? what is the parsing steps used to make Maple generate the above output? 

Maple 2016.

Why does

int(sqrt(c+d*tan(e+f*x))*(a+b*tan(e+f*x))^(5/2),x);

Causes mserver.exe to hang into a loop at full CPU and maple hangs?

Windows 7, 64 bit.  Even using timelimit() on it, it still hangs exceeding the time limit and never return. I have to kill mserver.exe or exit Maple to recover.