An obstacle can be to survival.Logical formLearned from8 sentences. An obstacle can be to aid.Logical formLearned from8 sentences. Obstacles may be attached.Logical formLearned from8 sentences. Efforts may encounter obstacles.Logical formLearned from8 sentences. An obstacle may get approval.Logical formLearned from8 sentences. An obstacle may stand in_front_of a (reform process).Logical formLearned from8 sentences. Obstacles can be to a resumption of a hunt.Logical formLearned from8 sentences. An obstacle can be at a stage.Logical formLearned from8 sentences. An obstacle may be lifted.Logical formLearned from8 sentences. A law may remove obstacles.Logical formLearned from8 sentences. An obstacle can be to harmony.Logical formLearned from8 sentences. An obstacle can be to an improvement of relations.Logical formLearned from8 sentences. Some obstacle can be for presidents.Logical formLearned from8 sentences. A plan may include a network of obstacles.Logical formLearned from8 sentences. An obstacle to a settlement can be a disagreement.Logical formLearned from8 sentences.