(Hiking trails) can be challenging.Logical formLearned from15 sentences. A trail can be a climb.Logical formLearned from15 sentences. Experts can be on a trail.Logical formLearned from15 sentences. Trails can be connected.Logical formLearned from15 sentences. A trail can be in use.Logical formLearned from15 sentences. A (paper trail) may pertain-to a female.Logical formLearned from15 sentences. Gaffes can be on a (campaign trail).Logical formLearned from15 sentences. A map may show trails.Logical formLearned from15 sentences. A trail can be watery.Logical formLearned from15 sentences. A trail can be in an area.Logical formLearned from15 sentences. Some feet can be constituted-of-or-filled-with trail.Logical formLearned from15 sentences. A trail can be rugged.Logical formLearned from15 sentences. A mesh can be constituted-of-or-filled-with trails.Logical formLearned from15 sentences. Trails can be worn.Logical formLearned from15 sentences. Authorities can be on a trail.Logical formLearned from15 sentences.