the sea-duty does not occur.
sent1: the sea-duty does not occur if the fact that the introduction happens or the isopteranness does not occur or both is false. sent2: the winding occurs.
$hypothesis$ = the sea-duty does not occur. ; $context$ = sent1: the sea-duty does not occur if the fact that the introduction happens or the isopteranness does not occur or both is false. sent2: the winding occurs. ; $proof$ = 
__UNKNOWN__