
From:  Mr. Brian B. McGuinness 
Subject:  Minor errors in the quick tour 
Date:  Wed, 15 Mar 2023 23:48:16 +0000 
These are a few things I noticed while glancing over the document:
In section 3.1.2, the sequence \a is shown as evaluating to both NUL and BEL. Checking with quad AV, it appears that \0 will produce NUL and \a will produce BEL.
In the table in section 3.4.9, the definition of equal has three circles, which looks wrong.
In section 3.4.12, note that stardieresis is the power operator, not the rank operator. For an integer right operand it repeats the operation the specified number of times. (if the integer is negative, it applies the inverse operation the number of times
given by the absolute value of the integer). So
1 (○⍣3) X or 1 ({circle}{stardieresis} 3) X is the sine of the sine of the sine of X, 1 (○⍣¯3) or 1 ({circle}{stardieresis} {negative}3) X is the arcsine of the arcsine of the arcsine of X, and so on.
Otherwise, I think that the quick tour is very nice. It has plenty of good examples to illustrate how things work. I also like the tables of functions and operators. It can serve as a nice introduction to APL for beginners.
 Brian McGuinness

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