Re: Free variables in an expression
- To: mathgroup at smc.vnet.net
- Subject: [mg54791] Re: Free variables in an expression
- From: "Jens-Peer Kuska" <kuska at informatik.uni-leipzig.de>
- Date: Wed, 2 Mar 2005 01:26:38 -0500 (EST)
- Organization: Uni Leipzig
- References: <d0142d$oon$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Hi, what is a "free (unbound)" variable. a) ?ValueQ ValueQ[expr] gives True if a value has been defined for expr, and gives False \ otherwise. b) without Hold[] you will never see the variables that have values because Mathematica will evaluate the expression until all variables with a value are replaced by the values Regards Jens "Sascha Kratky" <notvalid at notvalid.com> schrieb im Newsbeitrag news:d0142d$oon$1 at smc.vnet.net... > Is there a Mathematica built-in function that gives a list of free > (unbound) variables in an arbitrary expression? > > Thanks, > Sascha >