<s>[INST] What is the point of an identity function if it's just the same as the original function? [/INST] An identity function can serve multiple purposes in the context of mathematics and computer programming. Because functions can be treated as objects, they can be used as part of a mathematical expression such as function convolution. In programming, a function may accept a "callback function" as an argument and use it to do something. If the programmer wants the values to be unchanged, they can use the identity function as the callback.</s>\ <s>[INST] What other, more mathematical applications does the identity function have? [/INST] 