Re: Domain of a function

*To*: mathgroup at smc.vnet.net*Subject*: [mg123228] Re: Domain of a function*From*: Andrzej Kozlowski <akoz at mimuw.edu.pl>*Date*: Mon, 28 Nov 2011 05:52:21 -0500 (EST)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com*References*: <j9b6lb$4sv$1@smc.vnet.net> <j9lpke$lif$1@smc.vnet.net> <201111270914.EAA07275@smc.vnet.net>

On 27 Nov 2011, at 10:14, Tutor wrote: > Element[x | Sqrt[2 + x], Reals]; what exactly does "|" in this case? The first argument of Element can be a pattern and the assertions is that everything that matches the pattern is real. So what kind things match the pattern? For one, x matches it. Also, Sqrt[2+x] matches it and nothing more does. In other words, both x and Sqrt[2+x] must be real. Andrzej Kozlowski

**Follow-Ups**:**Re: Domain of a function***From:*Andrzej Kozlowski <akoz@mimuw.edu.pl>

**References**:**Re: Domain of a function***From:*Tutor <alfred.muehlleitner@gmx.at>