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 13!:16 Withdrawn initial writing: 2003-05-15last updated: 2004-10-26

The conjunction 13!:16 Trace has been withdrawn and replaced by the script system\packages\misc\trace.ijs . The 13!:16 implementation required complications in the interpreter unwarranted by the amount of benefit, and having the trace as a script provides a model of the J parser whose internal workings can be examined and experimented with.

The main function in the script is trace :
 x trace y trace expression y to x levels of function calls trace y same as _ trace y

Examples:
```   trace '3+i.4'
--------------- 1 Monad ------
i.
4
0 1 2 3
--------------- 2 Dyad -------
3
+
0 1 2 3
3 4 5 6
==============================
3 4 5 6

trace 'plus=: +'
--------------- 7 Is ---------
plus
=:
+
+
==============================

trace 'sum=: plus/'
--------------- 3 Adverb -----
plus
/
plus/
--------------- 7 Is ---------
sum
=:
plus/
plus/
==============================

trace 'sum p: 2+i.3'
--------------- 1 Monad ------
i.
3
0 1 2
--------------- 2 Dyad -------
2
+
0 1 2
2 3 4
--------------- 1 Monad ------
p:
2 3 4
5 7 11
--------------- 0 Monad ------
sum
5 7 11
------------------------------
plus/
5 7 11
------------------------------
7
+
11
18
==============================
5
+
18
23
==============================
23
==============================
23
==============================
23

mean=: sum % #

1 trace 'mean"1 *: i.2 3'
--------------- 1 Monad ------
i.
2 3
0 1 2
3 4 5
--------------- 4 Conj -------
mean
"
1
mean"1
--------------- 1 Monad ------
*:
i.2 3
0  1  4
9 16 25
--------------- 0 Monad ------
mean"1
2 3\$0 1 4 9 16 25
------------------------------
sum % #
0 1 4
1.6666666666666667
==============================
sum % #
9 16 25
16.666666666666668
==============================
1.66667 16.6667
==============================
1.66667 16.6667
```

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