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From: rockwell@socrates.umd.edu (Raul Deluth Miller-Rockwell)
Subject: Re: Function evaluation in J
In-Reply-To: HAC041@DJUKFA11.BITNET's message of 28 Apr 92 16:57:11 GMT
Message-ID: <ROCKWELL.92Apr28233027@socrates.umd.edu>
Sender: rockwell@socrates.umd.edu (Raul Deluth Miller-Rockwell)
Organization: Traveller
References: <92115.154130HAC041@DJUKFA11.BITNET> <ROCKWELL.92Apr24214315@socrates.umd.edu>
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	<ROCKWELL.92Apr28002419@socrates.umd.edu>
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Date: Wed, 29 Apr 1992 04:30:27 GMT

Konrad Hinsen:
   My criticism is that the definition is not clear; it states "u&v y
   is u v y and x u&v y is (v x)u(v y)". This however is simply not
   true, typing the first and the second expression gives different
   results in general, due to the different ranks. Since it is not
   possible to change the rank of a sequence of function calls (only
   the rank of individual function calls can be modified using "),
   there is no expression equivalent to u&v y but not using &, so
   defining & in terms of such a sequence is misleading.

What?

Let's give your original example a rank of zero:

   testa =.  '< |. > y.':''   "0

Now, the dictionary says that that function should be the same as this
one, when applied monadically:

   testb =.  < @|. @>

What is it about this that is unclear, not true, or misleading?

-- 
Raul Deluth Miller-Rockwell                   <rockwell@socrates.umd.edu>
