Dear Gretl Masters (Allin and Jack ;)),
I did a review of hansl-primer-a4.pdf (learning hansl), and found very few defects (one or two):
Chapter 7. Control flow, page 27
scalar x = 1
loop foreach f sqrt exp ln
scalar y = $f(1)
print y
endloop
(Unused "scalar x = 1" )
Chapter 10. Series and Lists, page 41
Another option for appending terms to, or dropping terms from, an existing list is to use += or +=, respectively, as in
xlist += cpi
zlist -= cpi