### Can I express an abstract, symbolic range of reals?

Hello,
I'm very new at sage.
I'd like to express a range like range(-3.0,3.0,0.02) but with symbols for all the parameters, like range(a,b,delta), that displays nicely with show(). I would like to be able to substitute in floats at some later stage.

a. I'm not sure what a conventional symbolic expression for a range of floats is

b. Not sure how to express ~~it.~~it in SageMath.

My goal is to be able to express constructing a chain rule over a finite input range. I seem to be able to express the chaining of functions ok, but am getting stuck with what i'm calling the constant function which is this range. If I use the range(-3.0,3.0,0.02) I get swamped by the output.

P.S. I don't want to use a built-in differentiate, I'm going to use finite differences.

Cheers...