Persian onager Persian onager The Persian onager ("Equus hemionus onager"), also called the Persian wild ass or Persian zebra, is a subspecies of onager (Asiatic wild ass) native to Iran. It is listed as Endangered, with no more than 600 individuals left in the wild and only 30 individuals living within North American institutions. The Persian onager is also simply named ', meaning "swift" in the Persian language, in which the word "gur" is preserved as the second syllable for ', which meant "donkey". Hence, onager. Sometimes, the term "onager" is reserved specifically for this subspecies. However, as the whole species of
Type system or an "effect system", which enables even more program specifications to be verified by a type checker. Beyond simple value-type pairs, a virtual "region" of code is associated with an "effect" component describing "what" is being done "with what", and enabling for example to "throw" an error report. Thus the symbolic system may be a "type and effect system", which endows it with more safety checking than type checking alone. Whether automated by the compiler or specified by a programmer, a type system makes program behavior illegal if outside the type-system rules. Advantages provided by programmer-specified type systems include: Advantages