/in/p2.cpp: In function 'int sum(list_t)':
/in/p2.cpp:33:12: error: 'accumulate' was not declared in this scope
     return accumulate(list, add, 0);
            ^~~~~~~~~~
/in/p2.cpp: In function 'int product(list_t)':
/in/p2.cpp:41:12: error: 'accumulate' was not declared in this scope
     return accumulate(list, times, 1);
            ^~~~~~~~~~
/in/p2.cpp: In function 'bool tree_hasPathSum_helper(tree_t, int)':
/in/p2.cpp:228:12: error: 'tree_hasPathSum' was not declared in this scope
     return tree_hasPathSum(tree_left(tree), sum - tree_elt(tree)) || tree_hasPathSum(tree_right(tree), sum - tree_elt(tree));
            ^~~~~~~~~~~~~~~
/in/p2.cpp:228:12: note: suggested alternative: 'tree_hasPathSum_helper'
     return tree_hasPathSum(tree_left(tree), sum - tree_elt(tree)) || tree_hasPathSum(tree_right(tree), sum - tree_elt(tree));
            ^~~~~~~~~~~~~~~
            tree_hasPathSum_helper