Re: Computing sets of equivalences

*To*: mathgroup at smc.vnet.net*Subject*: [mg46614] Re: Computing sets of equivalences*From*: "Simons, F.H." <F.H.Simons at tue.nl>*Date*: Wed, 25 Feb 2004 13:07:07 -0500 (EST)*Sender*: owner-wri-mathgroup at wolfram.com

Here is another solution of the problem. It is based on constructing a function that is constant on each equivalence class and has different values on different classes. equivalences[lst_List] := Block[{f}, Scan[(f[#[[1]]]=f[#[[2]]]=Unique[x])&,lst]; Scan[(Evaluate[f[#[[1]]]]=f[#[[2]]])& , lst]; Reap[Sow[#, f[#]]& /@ Union@@lst][[2]]] Only for large intial sets of initial equivalences Carl Woll's solution seems to be slightly faster. Regards, Fred Simons Eindhoven University of Technology