there exists something such that if the fact that it is sane and is not a cockatrice is false it is not a kind of a plainclothesman.
sent1: something is not a plainclothesman if the fact that it is sane and is not a kind of a cockatrice is not correct.
sent1 -> int1: the cockney is not a kind of a plainclothesman if that it is sane and is not a kind of a cockatrice is incorrect.; int1 -> hypothesis;
$hypothesis$ = there exists something such that if the fact that it is sane and is not a cockatrice is false it is not a kind of a plainclothesman. ; $context$ = sent1: something is not a plainclothesman if the fact that it is sane and is not a kind of a cockatrice is not correct. ; $proof$ = 
sent1 -> int1: the cockney is not a kind of a plainclothesman if that it is sane and is not a kind of a cockatrice is incorrect.; int1 -> hypothesis; __PROVED__