First, we do not have functions. We only have subroutines that read or write existing memory space. The language resembles assembly language, but is actually high-level. A subroutine may define local memory (equivalent to the stack frame), but all of that is lost when the subroutine completes.
# Approximately convert fahrenheit to celsius
subroutine fahren-to-celsius {
read f32 fahren
write f32 celsius
# temp is not necessary here, but used for illustrative purposes
local f32 temp
# copy the fahren value into temp. Not that '\n' and ';' are interchangable