Eroare de compilare in evaluator: user.cpp:20:31: warning: multi-character character constant user.cpp:4: error: declaration does not declare anything user.cpp: In function 'int main()': user.cpp:8: error: 'a' was not declared in this scope user.cpp:8: error: 'b' was not declared in this scope user.cpp:8: error: 'c' was not declared in this scope user.cpp:14: error: 'x' was not declared in this scope