main_ :: Method
main_ [] this wb k = 
  Assign n (Val (I 2000)) $
  Assign x (Sync primality_test [n]) $
  k
main_ :: Method
main_ [] this wb k = 
  Assign n (Val (I 2000)) $
  Assign x (Sync primality_test [n]) $
  k
main_ [] this wb k = 
  Assign n (Val (I 2000)) $
  Assign x (Sync primality_test [n]) $
  k