Models, in both science and mathematics, need to be internally consistent and also ought to be falsifiable (capable of disproof).
Təmusnawen, atamosan dǎɣ təmusne ən maɗinan, anihaganen adiqil ašohatnen dǎɣ amas əd anihaga deɣqanen adiqilan atiwisimutuyan (adoben adiqil ayugayan).