A (water filter) may pertain-to a person.Logical formLearned from44 sentences. Filters can be used.Logical formLearned from44 sentences. Filters can be effective.Logical formLearned from44 sentences. Filters may undergo a use.Logical formLearned from43 sentences. An (air filter) can be dirty.Logical formLearned from43 sentences. A list can be constituted-of-or-filled-with filters.Logical formLearned from43 sentences. A filter can be clean.Logical formLearned from43 sentences. A filter can be protective.Logical formLearned from43 sentences. Filters can be automated.Logical formLearned from42 sentences. Filters can be specialized.Logical formLearned from42 sentences. Persons may have a filter.Logical formLearned from42 sentences. A (spam filter) may pertain-to persons.Logical formLearned from41 sentences. A person may make a filter.Logical formLearned from41 sentences. Filters can be dirty.Logical formLearned from41 sentences. A filter can be in place.Logical formLearned from41 sentences.