@Carl Love Thanks for pointing that out to me. I have noticed it often enough, so I should know better. It always has had to do with < or > and maybe only after I edit an already posted reply.

I haven't made actual experiments with this, only noticed it and been quite annoyed by it.

I have inserted the intended lines again. Hopefully, they will remain as intended.

@Carl Love Thanks for pointing that out to me. I have noticed it often enough, so I should know better. It always has had to do with < or > and maybe only after I edit an already posted reply.

I haven't made actual experiments with this, only noticed it and been quite annoyed by it.

I have inserted the intended lines again. Hopefully, they will remain as intended.

@Markiyan Hirnyk My point was (as I also said) that the names the results from evalf  are assigned to have nothing to do with any unpredictable behavior by evalf. I was not criticizing your example as such, just that it didn't make that point.

@Markiyan Hirnyk My point was (as I also said) that the names the results from evalf  are assigned to have nothing to do with any unpredictable behavior by evalf. I was not criticizing your example as such, just that it didn't make that point.

If you give us the code as text, then you are more likely to get a response.

But clearly something like diff(x(0),t) would evaluate to zero resulting in 0=0 in the initial conditions.

You need to write D(x)(0)=0 instead.

But the variable names have nothing to do with it though.

restart;
with(RandomTools):
s := evalf(Generate(list(rational(denominator = 30), 10)));
s1 := evalf(Generate(list(rational(denominator = 30), 10)));
restart;
with(RandomTools):
s1 := evalf(Generate(list(rational(denominator = 30), 10)));
s := evalf(Generate(list(rational(denominator = 30), 10)));

But the variable names have nothing to do with it though.

restart;
with(RandomTools):
s := evalf(Generate(list(rational(denominator = 30), 10)));
s1 := evalf(Generate(list(rational(denominator = 30), 10)));
restart;
with(RandomTools):
s1 := evalf(Generate(list(rational(denominator = 30), 10)));
s := evalf(Generate(list(rational(denominator = 30), 10)));

A version not using identify:

interface(displayprecision=5);
evalindets(k,numeric,evalf[18]):
evalindets(%,`^`,x->op(1,x)^convert(op(2,x),rational));

A version not using identify:

interface(displayprecision=5);
evalindets(k,numeric,evalf[18]):
evalindets(%,`^`,x->op(1,x)^convert(op(2,x),rational));

@Axel Vogt Maple agrees:

sum(2*k-1,k=1..n);
expand(%);

@Axel Vogt Maple agrees:

sum(2*k-1,k=1..n);
expand(%);

Did you try the code in my comment? It reproduces the graphs on the top of page 5 rather exactly. It uses equtions 13 and 14. By r^2 is meant the inner product of r with r, i.e. <x,y>.<x,y> = x^2 + y^2.

Did you try the code in my comment? It reproduces the graphs on the top of page 5 rather exactly. It uses equtions 13 and 14. By r^2 is meant the inner product of r with r, i.e. <x,y>.<x,y> = x^2 + y^2.

@kagestodder r = (x, y) :

V2:=unapply(V(x,y)-11/2000*(x^2+y^2),x,y);
p1:=plot(V(x,0),x=-15..15,-5..0,caption="Gravitational potential"):
p2:=plot(V2(x,0),x=-15..15,-5..0,caption="Pseudo-potential"):
plots:-display(Array([p1,p2]));

@kagestodder r = (x, y) :

V2:=unapply(V(x,y)-11/2000*(x^2+y^2),x,y);
p1:=plot(V(x,0),x=-15..15,-5..0,caption="Gravitational potential"):
p2:=plot(V2(x,0),x=-15..15,-5..0,caption="Pseudo-potential"):
plots:-display(Array([p1,p2]));