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طرفي که دروست حرف الا
تكمیل کن و مثل آن را
بر طرف دگر فزون كن اي حبر
در مصطلح است نام این جبر
هنگام معادله تو بشناس
افتد اگر این که بعض اجناس
با وصف تجانس از سویت
در هر طرف اند بي مزيت
باید که زهر دو سو براني
نامش تو مقابله بخواني
“Complete the side in which the expression illā (less, minus) occurs, and add as much to the other side, O learned man: this is in correct language called jebr. In making the equation mark this: it may happen that some terms are cognate and equal on each side, without distinction; these you must on both sides remove, and this you call mokābalah.”
With the knowledge of Algebra, its Arabic name was introduced into Europe. Leonardo Bonacci of Pisa, when beginning to treat of it in the third part of his treatise of arithmetic, says: Incipit pars tertia de solutione quarundam quæstionum secundum modum Algebræ et Al-mucabulæ, scilicet oppositionis et restaurationis. That the sense of the Arabic terms is here given in the inverted order, has been remarked by Cossali. The definitions of jebr and mokābalah given by another early Italian
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