fib_work1 =: monad define 'fib_work_iter 1 1 , y.'

fib_work_iter =: monad define script
('a' ; 'b' ; 'count') =. y.
if. count = 0
  do. b
  else. fib_work_iter (1 + a + b) , a , count - 1
end.
)