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


"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
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AUSTRALIA                            http://physics.uwa.edu.au/~paul

            God IS a weakly left-handed dice player
____________________________________________________________________




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