Consider the following premises. Mary is drinking water if and only if Charles is playing squash. Charles is playing squash or Mary is not drinking water. Can we infer the following from them? The fact that Charles plays squash does not imply that Mary is drinking water.
 From the fact that Charles is playing squash or Mary is not drinking water we can infer that if Mary drinks water, then Charles is playing squash. Finally, from the fact that Mary is drinking water if and only if Charles is playing squash we can infer that if Charles plays squash, then Mary is drinking water, which contradicts that The fact that Charles plays squash does not imply that Mary is drinking water. Therefore, the answer is no.