there is something such that if it is not an intangible it is not a ichthyosaur.
sent1: if something is an intangible the fact that it is not a ichthyosaur is not incorrect. sent2: if the sild is not an intangible it is a kind of a ichthyosaur. sent3: there is something such that if it is an intangible it is not a kind of a ichthyosaur. sent4: there exists something such that if it is not an intangible then it is a ichthyosaur. sent5: the sild is not a ichthyosaur if it is a kind of an intangible. sent6: something is not a ichthyosaur if it is not a kind of an intangible. sent7: something is a kind of a ichthyosaur if it is not intangible.
sent6 -> int1: the sild is not a ichthyosaur if it is not intangible.; int1 -> hypothesis;
$hypothesis$ = there is something such that if it is not an intangible it is not a ichthyosaur. ; $context$ = sent1: if something is an intangible the fact that it is not a ichthyosaur is not incorrect. sent2: if the sild is not an intangible it is a kind of a ichthyosaur. sent3: there is something such that if it is an intangible it is not a kind of a ichthyosaur. sent4: there exists something such that if it is not an intangible then it is a ichthyosaur. sent5: the sild is not a ichthyosaur if it is a kind of an intangible. sent6: something is not a ichthyosaur if it is not a kind of an intangible. sent7: something is a kind of a ichthyosaur if it is not intangible. ; $proof$ = 
sent6 -> int1: the sild is not a ichthyosaur if it is not intangible.; int1 -> hypothesis; __PROVED__