@mmcdara 

Hello,

I think that this is not true in the general case. For instance if

G := (x,y) -> -(1 - x*y - (1 - x)*(1 + x - 1.2*x^2)*(1 - y)*(1 + y - 1.2*y^2))

Maple gives the right answer -1 with

minimize(K(x,y),x=0..1,y=0..1)

but this cannot be obtained restricting the function to y=x.

@acer 

Yes now it works fine!

Thanks, Nicola

@mmcdara 

Hello, I obtain that error even with the file that you uploaded.

My Maple version:

`Maple 2022.2, APPLE UNIVERSAL OSX, Oct 23 2022, Build ID 1657361`

Thank you for your suggestions. I still have these problems:

1. I can't see the cursor in the input (white) lines.

2. I can't change the color of the Maple Output. It's always blu whatever color I chose in Styles

@John Fredsted Thank you. Now it works fine.