A) | Conversation with a native speaker who allows you to do
most of the talking.
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B) | Reading material of interest in its own right.
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C) | Learning how to use dictionaries and grammars so as
to become independent of teachers.
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D) | Attempting to write on any topic of interest in itself.
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E) | Paying attention to the structure of words
so that known words will provide clues to the unknown.
For example, program (already analyzed) is related
to tele (far off) gram, which is in turn related
to telephone. Even tiny words may possess
informative structure: atom means not cuttable,
from a (not) and tom (as in tome and
microtome).
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A) | The computer provides for precise and general conversation.
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B) | Texts such as
Fractals, Visualization and J [7],
Exploring Math [8], and
Concrete Math Companion [14]
use the language in a variety of topics.
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C) | The appended dictionary of J provides a complete
and concise dictionary and grammar.
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D) | J Phrases [9] provides guidance
in writing programs, and almost any topic provides problems of
a wide range of difficulty.
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E) | Words possess considerable structure, as in +:
and -: and *: and %: for double,
halve, square, and square root.
Moreover, a beginner can assign and use mnemonic names appropriate
to any native language, as in sqrt=:%: and entier=:<.
(French name) and sin=:1&o. and SIN=:1&o.@(%&180@o.)
(for sine in degrees).
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< Left a (angle) | / Slash | & Amp (ersand) | % Per (cent) |
[ Left b (racket) | \ Back (slash) | @ At | ; Semi (colon) |
{ Left c (urly bracket) | | Stile | ^ Caret | ~ Tilde |
( Left p (arenthesis) | _ (Under) Bar | ` Grave | * Star |
Exercises
9.1 | Experiment with a revised version of the program MAP
of Exercise 7.1, using the remainder or residue
dyad (|) instead of the minimum (<.),
as in M=:map@(6&|) and compare its results with those
of MAP.
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9.2 | Experiment with the programs sin and SIN
defined in this section.
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9.3 | Write programs using various new primitives found in the
vocabulary at the end of the book.
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9.4 | Update the table of notation prepared in Exercise 2.2.
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