Let
be a staircase function and let
be a function. Prove that the composite g ∘ f {\displaystyle {}g\circ f} is also a staircase function.
![{\displaystyle f\colon [a,b]\longrightarrow [c,d]}](https://wikimedia.org/api/rest_v1/media/math/render/svg/0e0bb24836a42c93b9d118cddbc7528646cd6ae1)
![{\displaystyle g\colon [c,d]\longrightarrow \mathbb {R} }](https://wikimedia.org/api/rest_v1/media/math/render/svg/17dc3d8bf0c4809449ed4cc12eb6c7aa19253006)
