premise: Women taking a stroll while using their cellular phones on the streets. hypothesis: A female is on her cellphone while walking.
entailment: Women are female, so whatever any number of women are doing is something that a female is doing; 'cellphone' is short for cellular phone; 'walking' is synonymous with 'taking a stroll'; 'on [her] cellphone' and 'using [their] phones' mean the same thing.