A functionality may be implemented as a subscription.Logical formLearned from2 sentences. A duration may undergo a subscription.Logical formLearned from2 sentences. Subscriptions can be to a package.Logical formLearned from2 sentences. (Access links) may undergo a subscription.Logical formLearned from2 sentences. Mechanisms may installs/un-install subscriptions.Logical formLearned from2 sentences. Some requirements can be for confirmation of a (subscription request).Logical formLearned from2 sentences. (Email subscription settings) may pertain-to a person.Logical formLearned from2 sentences. A subscription can be to an institution.Logical formLearned from2 sentences. A company may sell (magazine subscriptions).Logical formLearned from2 sentences. (Subscription information) may be found.Logical formLearned from2 sentences. A subscription may include access to a site by e-mail.Logical formLearned from2 sentences. (Subscription trees) may pertain-to some applications.Logical formLearned from2 sentences. An (operator graph) can be a combination of (subscription trees).Logical formLearned from2 sentences. A combination may pertain-to (subscription trees).Logical formLearned from2 sentences. A target can be for subscription.Logical formLearned from2 sentences.