Question: Problem when calling implicitplot on an expression containing an integral

Hi there,

I'm having a problem when attempting an implicitplot of an expression containing an integral.

Here is a minimal example of what I'm trying to do:

restart: with(plots): with(DEtools):
f:= t-> t^(-2);
F:= x-> Int(f(t), t=x..1);
G:= (x,y) -> evalf(F(x)-y): G(x,y);
implicitplot(G(x,y), x=0..1, y=0..1);
plots[implicitplot](G(x,y), x=0..1, y=0..1, grid=[100,100]);

The above results in the following error message:

Error, (in plots/implicitplot) invalid input: the following extra unknowns were found in the input expression: {t}

The problem seems to come from the fact that Maple does not know how to compute the integral, because if I set instead
f:= t-> t^(2);
then the call to implicitplot works.

Since I would like a plot, I'm obviously happy to look for an approximation.

I have tried combinations of the following alternative calls, but it does not help.
F:= x-> int(f(t), t=x..1);
G:= (x,y) -> eval(F(x)-y): G(x,y);

Is my syntax muddled?

I am using Maple 11. I am saying this because I found this discussion that seems to report a similar problem
http://www.mapleprimes.com/forum/implicitploterror
and seems to suggest that Maple 11 is responsible. I have neither Maple 12 nor Maple 10 at hand, so I'd be very grateful for a workaround or solution.

Many thanks,

Patrick.