Re: Placing the "&"

*To*: mathgroup at smc.vnet.net*Subject*: [mg114857] Re: Placing the "&"*From*: Themis Matsoukas <tmatsoukas at me.com>*Date*: Mon, 20 Dec 2010 00:41:23 -0500 (EST)

Ziloo, I am not sure what you mean by "once a pure function becomes an argument for another standard function [...]". A pure function is the entire construct that includes # and ends with &. Maybe you are referring to the # as the pure function? That's only the placeholder for the dummy variable. For example, in PrimeQ[2^(#)+1]& the pure function is the entire line, not just the #. The above is equivalent to the standard function, f[x_]:= PrimeQ[2^(x)+1] Compare now PrimeQ[2^(#) + 1] &[2] and f[2]. They both evaluate the function at x=2 and give the same answer. Does this help? Themis