The problem is fairly subtle, but it boils down to the fact that input_box wants a *string* as default value , because a string is also what it gets from the user. Note that your names x and y are bound to x(t) and y(t) respectively. Input box turns its default parameter to a string, so the expression 3*x-2*y turns into the string "3*x(t)-2*y(t)".
Later when this is evaluated, it is evaluated in the context of the global bindings that are currently in force in your sage session, so with x,y being bound to x(t) and y(t) this turns into evaluating 3*x(t)(t)-2*y(t)(t) for which the deprecation warning is entirely correct. The solution is to quote your arguments to input_box as strings, i.e., ... input_box(default = "3*x - 2*y") ... -- You received this message because you are subscribed to the Google Groups "sage-support" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-support+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/sage-support/7af11856-1e50-43d4-9718-82ac49fdbb70%40googlegroups.com.
