(tu52.txt)
Next put the text of file 'test.mat' on the screen by typing MT
Read MT and note how code lines with labels as L0) and L1) are 
treated by verb "testof".
Note also how code lines are split at the occurance of verb "do"
When stepping through the code with C+E and E avoid labels and code sections
such as "do goto,'L1'" as these cause spurious error messages.
Also note that VT (the segmented string) and MT contain identical info
at the start. Any corrections and changes caused by verbs fix and new
change VT but not MT. This allows you to record changes as you go along
till you reach a stage where you want to recheck the code.
In that case use verb "refile" after which "test.mat" is changed and you
can restart the testing with "testof test" now with improved code.
If you don"t like this procedure you can also update file 'test.mat'
with edasc 'test.mat'. In that case you better make notes of intended
changes and incorporate them in one editing step with edasc.
When you have completed your checking you can direct "refile" to create
a new file "test.sc" or you can do this also using "mat2scr 'test'"
Then you have still to run verb "test" as an J-program. Erase "test.mat"
after you have changed "test.sc"
Except if you need to make whole-sale changes to the code, all of the above
is done in one J-session. The process also allows you after some experience
to check and if needed modify, a chain of verbs and subverbs in one session.