foo.cc:6:9: error: expected initializer before 'int'
    6 |         int i, j, nb;
      |         ^~~
foo.cc:8:9: error: expected unqualified-id before 'for'
    8 |         for (i = 100000; i >= 0; i--)
      |         ^~~
foo.cc:8:26: error: 'i' does not name a type
    8 |         for (i = 100000; i >= 0; i--)
      |                          ^
foo.cc:8:34: error: 'i' does not name a type
    8 |         for (i = 100000; i >= 0; i--)
      |                                  ^
foo.cc:16:9: error: expected unqualified-id before 'for'
   16 |         for (i = 0; i < nb; i++)
      |         ^~~
foo.cc:16:21: error: 'i' does not name a type
   16 |         for (i = 0; i < nb; i++)
      |                     ^
foo.cc:16:29: error: 'i' does not name a type
   16 |         for (i = 0; i < nb; i++)
      |                             ^
foo.cc:17:29: error: 'j' does not name a type
   17 |                 for (j = 0; j < nx; j++)
      |                             ^
foo.cc:17:37: error: 'j' does not name a type
   17 |                 for (j = 0; j < nx; j++)
      |                                     ^
foo.cc:19:9: error: expected unqualified-id before 'for'
   19 |         for (i = 0; i < nb + nx + 1; i++)
      |         ^~~
foo.cc:19:21: error: 'i' does not name a type
   19 |         for (i = 0; i < nb + nx + 1; i++)
      |                     ^
foo.cc:19:38: error: 'i' does not name a type
   19 |         for (i = 0; i < nb + nx + 1; i++)
      |                                      ^
foo.cc:24:9: error: expected unqualified-id before 'for'
   24 |         for (i = 0; i < nb + nx + 1; i++)
      |         ^~~
foo.cc:24:21: error: 'i' does not name a type
   24 |         for (i = 0; i < nb + nx + 1; i++)
      |                     ^
foo.cc:24:38: error: 'i' does not name a type
   24 |         for (i = 0; i < nb + nx + 1; i++)
      |                                      ^
foo.cc:26:1: error: expected declaration before '}' token
   26 | }
      | ^
foo.cc: In function 'int main()':
foo.cc:40:17: error: 'mul' was not declared in this scope
   40 |                 mul(b, xx, nx, k);
      |                 ^~~

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