in this proposition, that 'the three angles of a triangle are equal to two right ones,' one who has seen and clearly perceived the demonstration of this truth knows it to be true, when that demonstration is gone out of his mind; so that at present it is not actually in view, and possibly cannot be recollected:
Adibidez, triangelu baten hiru angeluek bi angelu zuzen osatzen dutela dioen proposizioan, egia honen frogapena ikusi eta argi hauteman duenak badaki egia dela, frogapenak gogamenetik alde egin dionean ere, orduan bistan ez eduki arren eta agian gogoratzerik ez eduki arren; baina lehen ez bezalako bidetik daki.