the clamshell is not urban.
sent1: the clamshell is urban and exempts mileage if there exists something such that it does exempt reactance. sent2: there is something such that it does exempt reactance.
sent2 & sent1 -> int1: the fact that the clamshell is a kind of urban thing that does exempt mileage is not false.; int1 -> hypothesis;
$hypothesis$ = the clamshell is not urban. ; $context$ = sent1: the clamshell is urban and exempts mileage if there exists something such that it does exempt reactance. sent2: there is something such that it does exempt reactance. ; $proof$ = 
sent2 & sent1 -> int1: the fact that the clamshell is a kind of urban thing that does exempt mileage is not false.; int1 -> hypothesis; __DISPROVED__