Re: Re: Debracketing array symbols

*To*: mathgroup at smc.vnet.net*Subject*: [mg92197] Re: [mg92159] Re: Debracketing array symbols*From*: Bob Hanlon <hanlonr at cox.net>*Date*: Tue, 23 Sep 2008 07:29:08 -0400 (EDT)*Reply-to*: hanlonr at cox.net

Clear[A] Head[A[1]] A A = Array[a, {4}] {a(1),a(2),a(3),a(4)} Head[A[1]] {a(1),a(2),a(3),a(4)} Consequently, if A were defined using A vice a on the RHS there would be an infinite recursion Bob Hanlon ---- carlos at Colorado.EDU wrote: ============= > deBracket[x_] := > x /. A_Symbol[n__Integer] :> > ToExpression[ > StringJoin[Prepend[ToString /@ {n}, ToString[A]]]] > > X[1] // deBracket > > X1 > > {A[1], A[2], A[3], A[4]} // deBracket Elegant. A related question A={A[1], A[2], A[3], A[4]} produces infinite recursion in 4.2 and 5.2 (NB - I prepare all coursework with 4.2 for compatibility with some remote students in industry) Is the symbol A used on the RHS? {A[1], A[2], A[3], A[4]} //FullForm just shows List[A[1],A[2],A[3],A[4]] which does not tell me much. Where is the role of A in the RHS explained in the documentation?. -- Bob Hanlon