✐‹creator "Kevin Kappelmann"› subsection ‹Orders› theory Predicates_Order imports HOL.Orderings begin lemma le_predI [intro]: assumes "⋀x. P x ⟹ Q x" shows "P ≤ Q" using assms by (rule predicate1I) lemma le_predD [dest]: assumes "P ≤ Q" and "P x" shows "Q x" using assms by (rule predicate1D) lemma le_predE: assumes "P ≤ Q" and "P x" obtains "Q x" using assms by blast declare le_boolD[dest] and le_boolI[intro] end