We first prove the second part of the Theorem. Now, we will prove the first part of the Theorem. The proof is by induction. The following auxiliary proposition is crucial to prove the theorem. A for the first attribute.

We appreciate suggestions from R6, 7, 8 and will include these in the paper. We have included most competitive methods with comparable settings to ours at the submission time. We will include the shown Algorithm 1. S sampled such that all attributes are present? However, our framework can compose features from any set S by solving Eq (10) even with missing attributes in S . Please notice that they are different.