A president may open a summit.Logical formLearned from24 sentences. An issue can be before a summit.Logical formLearned from24 sentences. Summits can be rugged.Logical formLearned from24 sentences. A summit can be controversial.Logical formLearned from24 sentences. A summit may be call_offed.Logical formLearned from24 sentences. Summits can be in a country.Logical formLearned from24 sentences. An outcome can be at a summit.Logical formLearned from23 sentences. A summit may be themed.Logical formLearned from23 sentences. An (european summit) may pertain-to a world-city.Logical formLearned from23 sentences. Parallel can be with a summit.Logical formLearned from23 sentences. A summit can be in history.Logical formLearned from23 sentences. A summit may end on a month.Logical formLearned from23 sentences. A (peace summit) may undergo a failure.Logical formLearned from23 sentences. A summit can be in the future.Logical formLearned from23 sentences. A summit may be scheduled on a month.Logical formLearned from23 sentences.