No I don't think i already know, that's why I asked you to explain.
In the most over-arching sense, tov ("good") means functional. And ra'a is negation or privation as dys-/mal-/non-function.
Ra'a is the latent quality within functionality that can be brought forth by addition as subtraction. Functionality, by it's very condition must have potentiality for negation of degrees of functionality. It's a qualitative consideration (anarthrous) rather than quantitative.
In one were to picture a mechanism with intricate functionality, such as gears and other moving parts; if one were to add a wrench (or whatever object) to the mechanism, it would subtract functionality.
A car being totally functional would have a change in that condition if sugar were added to the fuel tank (and thus introduced to the internal combustion process of the engine). This addition subtracts from function.
The serpent added to God's words, negating them in a pattern that induced deception. Eve, rather than refusing to listen and adhering to God's words, communicated with the serpent and heard another word. This horizontal external communication abrogated vertical internal constant communion of spiritual life (zoe) with/from God, and thus was the spiritual death (thanatos - cessation of communion with environment of origin) that resulted in the condition of sin (as a noun), the wages of which would be physical death (again, thanatos as cessation of communion for the body and its environment of origin - this cosmos).
Ra'a indirectly comes from tov if tov is added to for subtraction. God creates ra'a in that He created the functionality that gets un-ed or non-ed by adding for negation.
There's much more, but that's a brief summary.