Problem with <<DiscreteMath`KroneckerDelta`

• To: mathgroup at smc.vnet.net
• Subject: [mg19025] Problem with <<DiscreteMath`KroneckerDelta`
• From: "Harold Artis" <hartes at aurora.nt.tuwien.ac.at>
• Date: Tue, 3 Aug 1999 13:44:56 -0400
• Organization: Vienna University of Technology, Austria
• Sender: owner-wri-mathgroup at wolfram.com

```I'm a newish Mathematica (3.0.1) user. I don't understand why:

<<DiscreteMath`KroneckerDelta`
Sum[Conjugate[x[-c+a ml]] (DiscreteStep[c]-DiscreteStep[c-ml]),{c,-d,e}]

yields a warning:
\$RecursionLimit::"reclim": "Recursion depth of \!\(256\) exceeded.

and no solution. Working with -Infinity, Infinty as limits alleviates
this problem, but it does not help with the sum I wanted to use
originally:

g[n_]:=DiscreteStep[n]-DiscreteStep[n-M]
rectf[n_]:=DiscreteStep[n]-DiscreteStep[n-M]
f[a_,c_]:=Conjugate[x[a*M-c]]*rectf[-c]
yf[n_]=Sum[(
Sum[x[b-c]*f[a,c]*h[n,n-b],{c,-Infinity,Infinity},{b,-Infinity,
Infinity}]+wf[a,n])*g[n-a*M],{a,0,N/M-1}]

I expected Mathematica to leave the sum unchanged (apart from probably
changing the summation indexes) but it also yields the same warning as
above.

Thanks

Harold

```

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