Install byacc by entering the following commands in the terminal:
sudo apt update sudo apt install byacc
public domain Berkeley LALR Yacc parser generator
This package provides a parser generator utility that reads a grammar specification from a file and generates an LR(1) parser for it. The parsers consist of a set of LALR(1) parsing tables and a driver routine written in the C programming language. It has a public domain license which includes the generated C.