Further Examples: Function (&)

Here is a pure function that squares its argument.

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You can pass an argument to pure functions just as if they were ordinary functions like Sin or Min.

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These use the shorthand notation for a pure function.

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MyHead uses the third argument of Function to define a version of Head that does not evaluate its arguments.

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If the argument comes in unevaluated, it will remain that way.

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This is in contrast to Head.

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This tests unevaluated products to see if they contain spurious zeros.

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This uses DeleteCases to delete the zeros so that the products do not evaluate to zero.

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Here is a held list of elements.

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This groups consecutive elements that have the same head.

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This does not work since the ordinary form of pure function will evaluate #1 and #2, which destroys the structure in expressions such as and .

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