
visfot kaa siddhant

shaastriya tark, antargyaanvaadi tark aur isi tarah kii taarkik pranaliyon mein, visfot kaa siddhant (, 'jhooth seey, kuchh bhee [anusaran kartaa haye]'; yaa), yaa chhadm-scotus kaa siddhant (duns scotus koo galat tareeke seey jimmedaar thaharaaya jaataa haye), vaha kaanoon haye jisake anusaar kissy bhee kathan koo virodhabhas seey saabit kiya jaa sakata haye. yaani, ack baar jaba ack virodhabhas kaa daavaa kiya jaataa haye, tou kissy bhee prastaav (unake nakaratmak sahit) kaa anuman lagaaya jaa sakata haye; ise deductive visfot key roop mein jaanaa jaataa haye.
iss siddhant kaa pramaan pahali baar 12veen shatabdi key francisi daarshanik villium off soisons dwara diyaa gayaa thaa. visfot key siddhant key kaaran, ack aupchaarik swayamsiddh pranali mein ack virodhabhas (asangati) kaa astitva vinashkari haye; kyonki kissy bhee kathan koo saabit kiya jaa sakata haye, yeh satya aur asatya kii avadhaaranaon koo tuchchh banaata haye. 20veen shatabdi key anta mein, ganit kii neenv parr russell key virodhabhas jaise virodhabhason kii khoj ney ganit kii poori sanrachana koo khatare mein daal diyaa. gottlob fraze, ernst zermelo, abraham frankell aur thoralf scholem jaise ganitvidon ney inn virodhabhason koo samaapt karane key liye sett siddhant koo sanshodhit karane mein bahut prayaas kiya, jisake parinamswarup aadhunik zermelo-frankell sett siddhant banaa.
siddhant key pradarshan key roop mein, dou virodhabhasi bayanon parr vichaar karein-"sabhi nimbu peele hotey hain" aur "sabhi nimbu peele naheen hotey hain"-aur maan leejiye kii donon hii sach hain. yadi aisaa haye, tou kuchh bhee saabit kiya jaa sakata haye, ee.jee.nimnalikhit tark kaa upayog karke, yeh daavaa kii "unicorn maujood hain":
inn samasyaon key ack alag samadhan mein, kuchh ganitvidon ney "paraconsistent logics" naamak tark key vaikalpik siddhant taiyar kiye hain, joe visfot key siddhant koo samaapt karate hain. yeye kuchh virodhabhasi bayanon koo anya sabooton koo prabhaavit kiye binaa saabit karane kii anumati dete hain.
prateekaatmak pratinidhitva.
prateekaatmak tark mein, visfot key siddhant koo nimnalikhit tareeke seey yojnabaddh roop seey vyakt kiya jaa sakata haih
pramaan.
neeche prateekaatmak tark kaa upayog karate hue siddhant kaa ack aupchaarik pramaan haye.
yeh parichay mein diye gaye anaupchaarik tark kaa kewal prateekaatmak sanskaran haye, jisamen sootra _ 1 "sabhi nimbu peele hain" aur sootra _ 2 "unicorn maujood hain" key liye khadaa haye. humm yeh maanate hue shuru karate hain kii (1) sabhi nimbu peele hotey hain aur (2) sabhi nimbu peele naheen hotey hain. iss prastaav seey kii sabhi nimbu peele hotey hain, humm anuman lagaate hain kii (3) yaa tou sabhi nimbu peele hotey hain yaa unicorn maujood hotey hain. lekin phir iss tathya seey kii sabhi nimbu peele naheen hotey hain, humm anuman lagaate hain kii (4) unicorn disjective syllogism dwara maujood hain.
shabdarthik tark.
siddhant key liye ack vaikalpik tark model siddhant seey utpann hotaa haye. ack vaakya sootra _ 1 vaakya sootra _ 4 key ack samooh kaa ack "shabdarthik parinam" haye kewal tabhi jaba sootra _ 4 kaa pratyek model sootra _ 1 kaa ack model haye. haalaanki, virodhabhasi sett sootra _ 7 kaa koee model naheen haye. ack fortiori, sootra _ 7 kaa koee model naheen haye joe sootra _ 2 kaa model naheen haye. iss prakaar, khaali roop seey, sootra _ 7 kaa pratyek model sootra _ 2 kaa ack model haye. iss prakaar sootra _ 2 sootra _ 7 kaa ack shabdarthik parinam haye.
paraconsistent logic.
paraconsist logics vikasit kiye gaye hain joe upa-vipareet-nirmaan operators key liye anumati dete hain. model-saiddhaantik paraconsist logician aksar iss dhaarana seey incar karate hain kii formula _ 14 kaa koee model naheen hoe sakata haye aur shabdarth pranali taiyar curr sakate hain jisamen aise model hain. vaikalpik roop seey, way iss vichaar koo aswikar karate hain kii prastaavon koo sahee yaa galat key roop mein vargeekrit kiya jaa sakata haye. pramaan-saiddhaantik paraconsist logics aamtaur parr ack visfot koo praapt karane key liye aavashyak charanon mein seey ack kii vaidhata seey incar karate hain, jisamen aamtaur parr vichhedansheel shabdansh, vichhedan parichay aur "reductio aid aberdam" shamil hain.
upayog karein.
visfot key siddhant kaa metaa-mathematical moolya yeh haye kii kissy bhee taarkik pranali key liye jahaan yeh siddhant haye, koee bhee vyutpann siddhant joe τρ (yaa ack samkaksh roop, sootra _ 15) saabit kartaa haye, bekaar haye kyonki isake sabhi kathan pramey bunn jaayenge, jisase satya koo jhooth seey alag karna asambhav hoe jaayega. kahane kaa matlab haye, visfot kaa siddhant shaastriya tark mein gair-virodhabhas key niyam key liye ack tark haye, kyonki isake binaa sabhi satya kathan arthaheen hoe jaate hain. 
binaa kissy poorv vipad key tark kii pramaan shakti mein kamee kii charcha nyuntam tark mein kii jaati haye.