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 star-dieresis 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}{star-dieresis} 3) X is the sine of the sine
of the sine of X, 1 (○⍣¯3) or 1 ({circle}{star-dieresis} {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
