diff --git a/examples/tptp/tptp5.lex.cpp b/examples/tptp/tptp5.lex.cpp
index afeebb30a..ece0fbf86 100644
--- a/examples/tptp/tptp5.lex.cpp
+++ b/examples/tptp/tptp5.lex.cpp
@@ -905,9 +905,9 @@ extern int yylex (void);
  */
 YY_DECL
 {
-	register yy_state_type yy_current_state;
-	register char *yy_cp, *yy_bp;
-	register int yy_act;
+	 yy_state_type yy_current_state;
+	 char *yy_cp, *yy_bp;
+	 int yy_act;
     
 #line 110 "tptp5.l"
 
@@ -966,7 +966,7 @@ YY_DECL
 yy_match:
 		do
 			{
-			register YY_CHAR yy_c = yy_ec[YY_SC_TO_UI(*yy_cp)];
+			 YY_CHAR yy_c = yy_ec[YY_SC_TO_UI(*yy_cp)];
 			while ( yy_chk[yy_base[yy_current_state] + yy_c] != yy_current_state )
 				{
 				yy_current_state = (int) yy_def[yy_current_state];
@@ -1827,9 +1827,9 @@ ECHO;
  */
 static int yy_get_next_buffer (void)
 {
-    	register char *dest = YY_CURRENT_BUFFER_LVALUE->yy_ch_buf;
-	register char *source = (yytext_ptr);
-	register int number_to_move, i;
+    	 char *dest = YY_CURRENT_BUFFER_LVALUE->yy_ch_buf;
+	 char *source = (yytext_ptr);
+	 int number_to_move, i;
 	int ret_val;
 
 	if ( (yy_c_buf_p) > &YY_CURRENT_BUFFER_LVALUE->yy_ch_buf[(yy_n_chars) + 1] )
@@ -1932,8 +1932,8 @@ static int yy_get_next_buffer (void)
 
     static yy_state_type yy_get_previous_state (void)
 {
-	register yy_state_type yy_current_state;
-	register char *yy_cp;
+	 yy_state_type yy_current_state;
+	 char *yy_cp;
     
 	yy_current_state = (yy_start);
 
@@ -1942,7 +1942,7 @@ static int yy_get_next_buffer (void)
 
 	for ( yy_cp = (yytext_ptr) + YY_MORE_ADJ; yy_cp < (yy_c_buf_p); ++yy_cp )
 		{
-		register YY_CHAR yy_c = (*yy_cp ? yy_ec[YY_SC_TO_UI(*yy_cp)] : 1);
+		 YY_CHAR yy_c = (*yy_cp ? yy_ec[YY_SC_TO_UI(*yy_cp)] : 1);
 		while ( yy_chk[yy_base[yy_current_state] + yy_c] != yy_current_state )
 			{
 			yy_current_state = (int) yy_def[yy_current_state];
@@ -1963,9 +1963,9 @@ static int yy_get_next_buffer (void)
  */
     static yy_state_type yy_try_NUL_trans  (yy_state_type yy_current_state )
 {
-	register int yy_is_jam;
+	 int yy_is_jam;
     
-	register YY_CHAR yy_c = 1;
+	 YY_CHAR yy_c = 1;
 	while ( yy_chk[yy_base[yy_current_state] + yy_c] != yy_current_state )
 		{
 		yy_current_state = (int) yy_def[yy_current_state];
@@ -1980,9 +1980,9 @@ static int yy_get_next_buffer (void)
 	return yy_is_jam ? 0 : yy_current_state;
 }
 
-    static void yyunput (int c, register char * yy_bp )
+    static void yyunput (int c,  char * yy_bp )
 {
-	register char *yy_cp;
+	 char *yy_cp;
     
     yy_cp = (yy_c_buf_p);
 
@@ -1992,10 +1992,10 @@ static int yy_get_next_buffer (void)
 	if ( yy_cp < YY_CURRENT_BUFFER_LVALUE->yy_ch_buf + 2 )
 		{ /* need to shift things up to make room */
 		/* +2 for EOB chars. */
-		register int number_to_move = (yy_n_chars) + 2;
-		register char *dest = &YY_CURRENT_BUFFER_LVALUE->yy_ch_buf[
+		 int number_to_move = (yy_n_chars) + 2;
+		 char *dest = &YY_CURRENT_BUFFER_LVALUE->yy_ch_buf[
 					YY_CURRENT_BUFFER_LVALUE->yy_buf_size + 2];
-		register char *source =
+		 char *source =
 				&YY_CURRENT_BUFFER_LVALUE->yy_ch_buf[number_to_move];
 
 		while ( source > YY_CURRENT_BUFFER_LVALUE->yy_ch_buf )
@@ -2632,7 +2632,7 @@ int yylex_destroy  (void)
 #ifndef yytext_ptr
 static void yy_flex_strncpy (char* s1, yyconst char * s2, int n )
 {
-	register int i;
+	 int i;
 	for ( i = 0; i < n; ++i )
 		s1[i] = s2[i];
 }
@@ -2641,7 +2641,7 @@ static void yy_flex_strncpy (char* s1, yyconst char * s2, int n )
 #ifdef YY_NEED_STRLEN
 static int yy_flex_strlen (yyconst char * s )
 {
-	register int n;
+	 int n;
 	for ( n = 0; s[n]; ++n )
 		;