Definition: In this task, you're given two sentences. Indicate if the first sentence clearly entails the second sentence (i.e., one can conclude the 2nd sentence by reading the 1st one). Indicate your answer with '1' if the first sentence entails the second sentence, otherwise answer with '0'.
Input: Sentence 1: The so-called "grandmother hypothesis", based on studies of African hunter-gatherer groups, suggests that infertile women are vital for successful child-rearing despite being unable to produce children themselves. Sentence 2: Infertile women are vital for successful child-rearing, according to the "grandmother hypothesis".

1