Simplify the following text for a Grade 7 native English-speaking person.
Original: The notion of computability of a function can be relativized to an arbitrary set of natural numbers A. A function f is defined to be computable in A ( equivalently A-computable or computable relative to A ) when it satisfies the definition of a computable function with modifications allowing access to A as an oracle .
Simplified: A Computable function is a notion from computer science .