Sentence 1: Heliair will have less than 21 % oxygen and will be hypoxic ( less than 17 % oxygen ) for mixtures with more than 20 % helium .
Sentence 2: Heliair will always have more than 21 % oxygen and will be hypoxic in mixtures with less than 20 % helium ( less than 17 % oxygen ) .
Question: Do Sentence 1 and Sentence 2 express the same meaning? Yes or No?