There is a button at the top right corner that has an icon that seems to say 4pi/3. When I hover over it is says "Maple Math". I click on it, and insert an expression that I copy directly from Maple: a simple definition of a function. There is an error that says "You have entered an invalid Maple expression". Why? The function is defined as z__1 := (x,y) -> x+y. Perhaps the issue is the subscript. I don't know but the UI does not tell me.
Here is an example that does not give an error in the form when I click the aforementioned "Maple Math" button. However, what I see below is a broken icon and the equation f := (x,y) -> x + y (exactly like this).
I am bewildered by the brokenness of this UI.