Talk:Normal form (abstract rewriting)

A basic knowledge of term rewriting systems is sufficient to understand this article; the technical and other tags are simply unjustified. Dysprosia 22:28, 10 May 2006 (UTC)

2 or 3

I reapplied User:Qwertyus' change in the example. The version with '3' is at least misleading, since it applies the rule twice in a single step, and the text doesn't say that $\rightarrow _{\rho }$ can be used in this way -- one would usually expect each $\rightarrow _{\rho }$ to mean just a single substitution. Even if there's an established usage for this, the fact that Qwertyus and I independently stumbled over this and initially thought it was wrong shows that this shouldn't be in an initial example because people can't be expected to be familiar with this usage.

"one" was also misleading, since there are several (in fact three) ways of eventually reducing the original expression to "4".

Granted, there are indeed two reductions taking place in one step, which isn't right; this could have been elucidated with a more extensive comment from Qwertyus. Maybe a better way of fixing the problem would be to add the extra step in the reduction instead of changing the reduction sequence altogether, this would demonstrate reduction more clearly. So the question is either revert and add an extra reduction step or leave it as it is? Dysprosia 07:48, 8 July 2006 (UTC)

Neither - I've added some plain English text to explain what it is being done. — Paul G 13:48, 27 October 2006 (UTC)

Make sure you are precise when you do this; the language is to speak of applying the reduction rule (more specifically, contracting redexes, but we need not get that technical here), not the function symbol that may occur. Dysprosia 14:12, 27 October 2006 (UTC)