Before revision:  One way to do so is erasure: a subset of inputs is considered irrelevant if it can be removed without affecting the model prediction. Despite its conceptual simplicity, erasureis not commonly used in practice. First, the objective is generally intractable , and approximate search or leave-one-out estimates are typically used instead;
After revision:  One way to do so is erasure: a subset of inputs is considered irrelevant if it can be removed without affecting the prediction. Though conceptually simple, erasure's objective is intractable and approximate search or leave-one-out estimates are typically used instead;