diff --git a/labs/04/lexAnalyzer.l b/labs/04/lexAnalyzer.l
new file mode 100644
index 0000000..8b2b9e2
--- /dev/null
+++ b/labs/04/lexAnalyzer.l
@@ -0,0 +1,33 @@
+%{
+#include <stdio.h>	
+%}
+
+%%
+"//".*				{ printf("COMMENT\n"); }
+"f"					{ printf("floatdcl\n"); }
+"i"					{ printf("intdcl\n"); }
+"p"					{ printf("print\n"); }
+[a-zA-Z]			{ printf("id\n"); }
+[0-9]+\.[0-9]+		{ printf("fnum\n"); }
+[0-9]+				{ printf("inum\n"); }
+"="					{ printf("assign\n"); }
+"+"					{ printf("plus\n"); }
+"-"					{ printf("minus\n"); }
+"*"					{ printf("multiply\n"); }
+"/"					{ printf("divide\n"); }
+[ \t\n]+			{ /* empty spaces */ }
+.					{ printf("UNKOWN CHAR '%s'\n", yytext); }
+%%
+
+int main(int argc, char **argv) {
+	if(argc > 1) {
+		FILE *file = fopen(argv[1], "r");
+		if(!file) {
+			perror("[!] Couldnt open file");
+			return 1;
+		}
+		yyin = file;
+	}
+	yylex();
+	return 0;
+}
\ No newline at end of file