sentence1: If three variables , formula _ 26 , formula _ 27 and formula _ 28 are bound by the condition formula _ 29 for some differentiable function formula _ 30 , then the following total differentials exist
sentence2: If three variables , Formula 26 , Formula 27 and Formula 28 , are bound for a total function formula 30 by condition formula 29 , the following differentials exist .