' Test and display primes 1 .. 50
for i = 1 TO 50
  if prime(i) <> 0 then print i;" ";
next i

FUNCTION prime(n)
if n < 2         then prime = 0 : goto [exit]
if n = 2         then prime = 1 : goto [exit]
if n mod 2 = 0   then prime = 0 : goto [exit]
prime = 1
for i = 3 to int(n^.5) step 2
 if n mod i = 0 then  prime = 0 : goto [exit]
next i
[exit]
END FUNCTION