Borel measurable function

Borel measurable function

[bȯ·rel ¦mezh·rə·bəl ′fənk·shən]
(mathematics)
A real-valued function such that the inverse image of the set of real numbers greater than any given real number is a Borel set.
More generally, a function to a topological space such that the inverse image of any open set is a Borel set.