negative pattern matching anyone?
- To: mathgroup at smc.vnet.net
- Subject: [mg43702] negative pattern matching anyone?
- From: Paolo Bientinesi <pauldj at cs.utexas.edu>
- Date: Tue, 30 Sep 2003 16:43:01 -0400 (EDT)
- Organization: University of Texas at Austin
- Sender: owner-wri-mathgroup at wolfram.com
Hello, could anyone explain me why -3 is different from -a in the following situation, please? h[-x_] := Abs[x] h[x_] := x^2 now, k[-3] = 9 k[-a] = Abs[a] I guess the answer con be found in the FullForm: FullForm[-a] = Times[-1,a] FullForm[-x_] = Times[-1,Pattern[x,Blank[]]] while FullForm[-3] = -3 Then, is there a way to match both -3 and -a with the same pattern? Thanks. -- Paolo pauldj at cs.utexas.edu paolo.bientinesi at iit.cnr.it