The *(term) for a relation among _(object)s within a given context determining their comparitive identity - whether they are the same or different from a given perspective. _(Programming language) design often involves determining a reasonable policy for answering this, involving issues such as _(level of abstraction|Abstraction Level), choices about determining the essential characteristics or attributes of an object, and linguistic value of expressions.

<ul class="links">
<li>_(Henry Baker)'s _(Object Identity and Immutability|http://www.pipeline.com/~hbaker1/ObjectIdentity.html)
<li>_(Kent M. Pitman)'s _(The Best of Intentions / EQUAL Rights--and Wrongs--in Lisp|http://www.nhplace.com/kent/PS/EQUAL.html)
<li>...
</ul>