Bison + Flex on C++ don't work

[Joao Pedro Abreu De Souza]

Hi folks. My friend Nicholas and I are trying to make a compiler for a
simpler language(just expressions by now) with flex and bison using C++.

Using
https://www.gnu.org/software/bison/manual/html_node/A-Complete-C_002b_002b-Example.html
as a guide, we code the repository below, but when We try

bison -d parser.yy -o parser.cc
lex scanner.l
g++ lex.yy.cc parser.cc main.cc -o cppimp


Give us the error in the file

repository : https://github.com/nicholas-barcelos/Cppimp

We try to change headers of place, move definitions of class, but nothing
work. What are we making wrong? Thanks in advance

log.txt
Description: Text document