Added some boiler plate to the .lex file

lexicalStructure.lex

@@ -0,0 +1,13 @@
+// Lexical Analysis with Flex (2.6.0) We used some of the code from this manual
+//                                    so we placed the citation here.
+//definitions
+%option noyywrap
+%{
+#include <typedefs.h>
+%}
+DIGIT   [0-9]
+ID      [a-zA-Z][a-zA-Z0-9]*
+%%
+//rules
+%%
+//user code