Re: Manipulation of equations and inequalities in "high-school style"

*To*: mathgroup at smc.vnet.net*Subject*: [mg19691] Re: Manipulation of equations and inequalities in "high-school style"*From*: Paul Abbott <paul at physics.uwa.edu.au>*Date*: Sat, 11 Sep 1999 16:36:00 -0400*Organization*: University of Western Australia*References*: <7q9hdf$o62@smc.vnet.net> <7r4voh$9qh@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

"William M. MacDonald" wrote: > I have repeatedly suggested to Wolfram technical staff, and to Stephen > Wolfram, that Equal be given the same properties for a single equation as > List, that Listable symbols operate on > > Equal[exp1,exp2] > > just as they do on > > List[exp1,exp2] But this is simple to implement! Following Roman Maeder, just enter the following code Unprotect[Equal]; listableQ[f_] := MemberQ[Attributes[f], Listable] Equal/: lhs:(f_Symbol)?listableQ[___, _Equal, ___] := Thread[Unevaluated[lhs], Equal] Protect[Equal]; ____________________________________________________________________ Paul Abbott Phone: +61-8-9380-2734 Department of Physics Fax: +61-8-9380-1014 The University of Western Australia Nedlands WA 6907 mailto:paul at physics.uwa.edu.au AUSTRALIA http://physics.uwa.edu.au/~paul God IS a weakly left-handed dice player ____________________________________________________________________