Ratsel is a translator using Lex and Yacc

To run the files-
Step1: Download the files        
Step2: Open the terminal 
Step3: compile 'yacc -d ratsel.y'
Step4: compile 'flex ratsel.l'
Step5: Run 'cc lex.yy.c y.tab.c -lfl'
Step6: ./a.out<input.r

input.r file is of ratsel format