Re: A variable defaulting to a previous variable?

*To*: mathgroup at smc.vnet.net*Subject*: [mg121958] Re: A variable defaulting to a previous variable?*From*: DrMajorBob <btreat1 at austin.rr.com>*Date*: Fri, 7 Oct 2011 04:48:07 -0400 (EDT)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com*References*: <201110060825.EAA22765@smc.vnet.net>*Reply-to*: drmajorbob at yahoo.com

Clear[f] f[x_] := f[x, x] f[x_, y_] := x + y f[2, 3] f[3] 5 6 Bobby On Thu, 06 Oct 2011 03:25:54 -0500, Brentt <brenttnewman at gmail.com> wrote: > How would one go about making a variable default to a previous variable? > > I would like results like this: > > In[1]= f[x_, y_: x] := x+y; >> In[2]= f[2,3] >> Out[1]= 5 >> In[3]= f[3] >> Out[1]= 6 >> > > > > But, of course, Mathematica won't let me use a previous argument for the > default of the next argument. Is there a way to do this? -- DrMajorBob at yahoo.com

**References**:**A variable defaulting to a previous variable?***From:*Brentt <brenttnewman@gmail.com>