    (1:0) const                   <--      (1:0) const
          ^                                      ^

    (1:6) nst fn =                <--      (1:6) nst fn = 
              ^                                      ^

    (1:8) t fn = (a               <--      (1:8) t fn = ar
              ^                                      ^

   (1:12)  = (arg)                <--     (1:11) n = arg =
              ^                                      ^

   (1:15) (arg) =>                <--     (1:14)  arg => {
              ^                                      ^

   (1:20)  => {                   <--     (1:18)  => {
              ^                                      ^

    (2:2)   var [                 <--      (2:2)   var _
            ^                                      ^

   (2:15) ] = arg;                <--     (2:40) ray(arg, 
              ^                                      ^

   (2:18)  arg;                   <--     (2:43) (arg, 2),
              ^                                      ^

    (2:7) ar [x, y]               <--      (3:4)     x = _
              ^                                      ^

    (2:8) r [x, y]                <--      (3:5)    x = _a
              ^                                      ^

   (2:10) [x, y] =                <--      (4:4)     y = _
              ^                                      ^

   (2:11) x, y] = a               <--      (4:5)    y = _a
              ^                                      ^

    (3:0) }                       <--      (5:0) };
          ^                                      ^

    (3:1) }                       <--      (5:1) };
           ^                                      ^
