A 21-year-old can be undefeated in some matches.Logical formLearned from2 sentences. Women can be undefeated at championships.Logical formLearned from2 sentences. A person can be undefeated in some singles.Logical formLearned from2 sentences. Welterweights can be undefeated.Logical formLearned from2 sentences. A (world number one) can be undefeated.Logical formLearned from2 sentences. Junior lightweight may remain undefeated.Logical formLearned from2 sentences. Some weeks of a tournament can be undefeated.Logical formLearned from2 sentences. Season may remain undefeated.Logical formLearned from2 sentences. A batsmen can be undefeated.Logical formLearned from2 sentences. Openers may remain undefeated.Logical formLearned from2 sentences. A dane may remain undefeated.Logical formLearned from2 sentences. (Service games) can be undefeated.Logical formLearned from2 sentences. A sports-celebrity can be undefeated in some ties.Logical formLearned from2 sentences. A person can be undefeated in some competitions.Logical formLearned from2 sentences. A (gold medallist) can be undefeated.Logical formLearned from2 sentences.