Experiences may prove disappointing.Logical formLearned from5 sentences. Slavery may prove an ability.Logical formLearned from5 sentences. A system may prove efficient.Logical formLearned from5 sentences. Elections may prove inconclusive.Logical formLearned from5 sentences. Searches may prove fruitless.Logical formLearned from5 sentences. Some tips may prove helpful.Logical formLearned from5 sentences. Research may prove that something-is-the-case.Logical formLearned from5 sentences. Attempts may prove effective.Logical formLearned from5 sentences. A person may be proven through fire.Logical formLearned from5 sentences. A country may prove costly.Logical formLearned from5 sentences. Persons may prove a guilt.Logical formLearned from5 sentences. A government may prove an element.Logical formLearned from5 sentences. An argument may prove a point.Logical formLearned from5 sentences. A philosopher may prove a good.Logical formLearned from5 sentences. An attempt may prove vain.Logical formLearned from5 sentences.