Re: Pattern matching in functions

*To*: mathgroup at smc.vnet.net*Subject*: [mg54388] Re: [mg54379] Pattern matching in functions*From*: Andrzej Kozlowski <akoz at mimuw.edu.pl>*Date*: Sun, 20 Feb 2005 00:07:48 -0500 (EST)*References*: <200502190732.CAA06160@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

On 19 Feb 2005, at 08:32, Maximilian Ulbrich wrote: > Hi, > > I would like to find subexpressions using Cases. > In the following case, I expected to find a[b] and a[c] and therefore > get {b,c} as the result. However, I get {l,l}. > What happens and how can I solve this? > > Cases[l^4*a[b][l] + l*a[c][l], x_a[y_] -> y, {0, Infinity}] > > Thanks, > Max > > > Cases[l^4*a[b][l] + l*a[c][l], x_a[y_] :> First[x], Infinity] {b,c} Andrzej Kozlowski Chiba, Japan http://www.akikoz.net/andrzej/index.html http://www.mimuw.edu.pl/~akoz/

**References**:**Pattern matching in functions***From:*Maximilian Ulbrich <mulbrich@berkeley.edu>