Yes, I believe that's correct. SUBRs arguments are evaluated before they are passed to the SUBR - this is effectively just normal a function familiar from othe

Yes, I believe that's correct. SUBRs arguments are evaluated before they are passed to the SUBR - this is effectively just normal a function familiar from other languages. I thinnk an FSUBR (or FEXPR) essentially gets the entire argument list unevaluated and then is responsible for evaluating that according to it's own desires.