In Rudin
Measurable function are defined as
$(X,M)$ is measurable space , $(U,\tau)$ is topological space f is said to be measurable function if for every open set $v\in \tau$ in U $f^{-1}(v)\in M $
In folland
Measurable function are defined as
$(X,M),(Y,N)$ are measurable spacef is said to be measurable function if for every open set $v\in N$ then $f^{-1}(v)\in M $ (i.e inverse image of measurable set is measurable )
I know that Measurable set and topological are different concept No one implies one another
So are they equivalent or not ?
Any Help will be appreciated