On Mon, March 19, 2012 4:10 pm, Raul Miller wrote: > For what it's worth, J's problem with 13 :'y+y' is probably something > like: > > original y+y > made tacit +~ > simplified +
Undoubtedly. > In other words, since + is commutative, the ~ is "unnecessary". > > Except, of course, that's only relevant for expressions like 13 :'x+y' > > So, anyways, I expect that the problem is that the rule that supports > simplification for commutative expressions has lost the context that > would be necessary to know that it's applicable. The problem appears to include the fact that we do not always provide sufficient context for tacit definitions, to specify whether a tacit verb is monadic, dyadic, or ambivalent. (We can, of course, using [: : d, or m : [:, or m : d .) However, when we start from an explicit definition, as in the case of 'y+x', the interpreter does have that information at the beginning, and should not throw it away during the "optimization" process, or as it is sometimes known in such cases, pessimization. > If I am right, the simple solution would be to remove that > simplification when the arguments are not available (which might be > always). But the problem occurs precisely when the arguments are available, as in 'y+y' or 'y+x'. > -- > Raul -- Edward Mokurai (默雷/धर्ममेघशब्दगर्ज/دھرممیگھشبدگر ج) Cherlin Silent Thunder is my name, and Children are my nation. The Cosmos is my dwelling place, the Truth my destination. http://wiki.sugarlabs.org/go/Replacing_Textbooks ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
