I hope not to raise too much the noise/signal level on list, but I have a
question: I have had a long experience programming my HP28s pocket
calculator, and its RPN language that AFAIK is mostly the same as that of
newer models, supported constructs of the form

  -> a b << ... >>

where C<< -> >> is a literal right arrow char and C<<< << >>> and C<<< >> 
>>> are literal guillemets (delimiting blocks). Just wonder wether by any 
chance *that* language has had any influence on the

  -> $x, $y { ... }

construct.