absolutely nothing dramatic here, but kind of strange. I had a missing
parenthesis in the following line (truncated by gretl in the error
refac = rescale ? sqrt( Teff / (Teff - rows(coeff) ) :
Erwartete ',' aber fand ':'
(The message says "expected ',' but found ':'.)
Somehow the parser never realized the unmatched parentheses. Maybe
because of the ternary statement?