Examine the variable a again.
-----------------------------------------------------
#? a
undef
#_
#R 11
34 23 1 * *
-----------------------------------------------------
009. print " ",t
010. if t > 1 then MyFunction t-1
>011. print " *"
012. end sub
013.
This is undef because now we examine the local variable. Issue the command u and examine the variable again.
#u
done
#?a
3
#_
Issuing the command u we stepped one level up in the call stack. At that point the variable a is global and has value. That is actually a different variable that happens to have the same name.
Issue the command l to see where we are.
-----------------------------------------------------
012. end sub
013.
>014. MyFunction a
015.
016. a = a + 2
-----------------------------------------------------
#
#l
To get one level deeper in the stack issue the command d.
-----------------------------------------------------
009. print " ",t
010. if t > 1 then MyFunction t-1
>011. print " *"
012. end sub
013.
-----------------------------------------------------
#_
#d
done
#l
If you stepped several levels up in the stack you should issue that many commands d or just one D to go to the bottom of the stack.