diff --git a/lualib.h b/lualib.h
index f0e253d6..1ad9b30e 100644
--- a/lualib.h
+++ b/lualib.h
@@ -2,7 +2,7 @@
 ** Libraries to be used in LUA programs
 ** Grupo de Tecnologia em Computacao Grafica
 ** TeCGraf - PUC-Rio
-** $Id: lualib.h,v 1.2 1994/08/24 15:29:02 celes Stab roberto $
+** $Id: lualib.h,v 1.3 1994/12/13 15:59:16 roberto Exp roberto $
 */
 
 #ifndef lualib_h
@@ -12,5 +12,11 @@ void iolib_open   (void);
 void strlib_open  (void);
 void mathlib_open (void);
 
+
+/* auxiliar functions (private) */
+void lua_arg_error(char *funcname);
+char *lua_check_string (int numArg, char *funcname);
+float lua_check_number (int numArg, char *funcname);
+
 #endif
 
diff --git a/mathlib.c b/mathlib.c
index 9dd39609..1092052a 100644
--- a/mathlib.c
+++ b/mathlib.c
@@ -3,7 +3,7 @@
 ** Mathematics library to LUA
 */
 
-char *rcs_mathlib="$Id: mathlib.c,v 1.11 1995/10/04 13:52:09 roberto Exp $";
+char *rcs_mathlib="$Id: mathlib.c,v 1.12 1995/10/09 12:48:38 roberto Exp roberto $";
 
 #include <stdio.h>		/* NULL */
 #include <math.h>
@@ -17,25 +17,9 @@ char *rcs_mathlib="$Id: mathlib.c,v 1.11 1995/10/04 13:52:09 roberto Exp $";
 #define TODEGREE(a) ((a)*180.0/PI)
 #define TORAD(a)    ((a)*PI/180.0)
 
-
-static void str_error(char *funcname)
-{
-  char buff[250];
-  sprintf(buff, "incorrect arguments to function `%s'", funcname);
-  lua_error(buff);
-}
-
-static float get_and_check_float (int numArg, char *funcname)
-{
-  lua_Object o = lua_getparam(numArg);
-  if (!lua_isnumber(o))
-    str_error(funcname);
-  return lua_getnumber(o);
-}
-
 static void math_abs (void)
 {
- double d = get_and_check_float(1, "abs"); 
+ double d = lua_check_number(1, "abs"); 
  if (d < 0) d = -d;
  lua_pushnumber (d);
 }
@@ -43,7 +27,7 @@ static void math_abs (void)
 
 static void math_sin (void)
 {
- double d = get_and_check_float(1, "sin");
+ double d = lua_check_number(1, "sin");
  lua_pushnumber (sin(TORAD(d)));
 }
 
@@ -51,7 +35,7 @@ static void math_sin (void)
 
 static void math_cos (void)
 {
- double d = get_and_check_float(1, "cos");
+ double d = lua_check_number(1, "cos");
  lua_pushnumber (cos(TORAD(d)));
 }
 
@@ -59,64 +43,64 @@ static void math_cos (void)
 
 static void math_tan (void)
 {
- double d = get_and_check_float(1, "tan");
+ double d = lua_check_number(1, "tan");
  lua_pushnumber (tan(TORAD(d)));
 }
 
 
 static void math_asin (void)
 {
- double d = get_and_check_float(1, "asin");
+ double d = lua_check_number(1, "asin");
  lua_pushnumber (TODEGREE(asin(d)));
 }
 
 
 static void math_acos (void)
 {
- double d = get_and_check_float(1, "acos");
+ double d = lua_check_number(1, "acos");
  lua_pushnumber (TODEGREE(acos(d)));
 }
 
 
 static void math_atan (void)
 {
- double d = get_and_check_float(1, "atan");
+ double d = lua_check_number(1, "atan");
  lua_pushnumber (TODEGREE(atan(d)));
 }
 
 
 static void math_atan2 (void)
 {
- double d1 = get_and_check_float(1, "atan2");
- double d2 = get_and_check_float(2, "atan2");
+ double d1 = lua_check_number(1, "atan2");
+ double d2 = lua_check_number(2, "atan2");
  lua_pushnumber (TODEGREE(atan2(d1, d2)));
 }
 
 
 static void math_ceil (void)
 {
- double d = get_and_check_float(1, "ceil");
+ double d = lua_check_number(1, "ceil");
  lua_pushnumber (ceil(d));
 }
 
 
 static void math_floor (void)
 {
- double d = get_and_check_float(1, "floor");
+ double d = lua_check_number(1, "floor");
  lua_pushnumber (floor(d));
 }
 
 static void math_mod (void)
 {
- int d1 = (int)get_and_check_float(1, "mod");
- int d2 = (int)get_and_check_float(2, "mod");
+ int d1 = (int)lua_check_number(1, "mod");
+ int d2 = (int)lua_check_number(2, "mod");
  lua_pushnumber (d1%d2);
 }
 
 
 static void math_sqrt (void)
 {
- double d = get_and_check_float(1, "sqrt");
+ double d = lua_check_number(1, "sqrt");
  lua_pushnumber (sqrt(d));
 }
 
@@ -147,10 +131,10 @@ static void math_pow (void)
 static void math_min (void)
 {
  int i=1;
- double dmin = get_and_check_float(i, "min");
+ double dmin = lua_check_number(i, "min");
  while (lua_getparam(++i) != LUA_NOOBJECT)
  {
-  double d = get_and_check_float(i, "min");
+  double d = lua_check_number(i, "min");
   if (d < dmin) dmin = d;
  }
  lua_pushnumber (dmin);
@@ -159,10 +143,10 @@ static void math_min (void)
 static void math_max (void)
 {
  int i=1;
- double dmax = get_and_check_float(i, "max");
+ double dmax = lua_check_number(i, "max");
  while (lua_getparam(++i) != LUA_NOOBJECT)
  {
-  double d = get_and_check_float(i, "max");
+  double d = lua_check_number(i, "max");
   if (d > dmax) dmax = d;
  }
  lua_pushnumber (dmax);
@@ -170,33 +154,33 @@ static void math_max (void)
 
 static void math_log (void)
 {
- double d = get_and_check_float(1, "log");
+ double d = lua_check_number(1, "log");
  lua_pushnumber (log(d));
 }
 
 
 static void math_log10 (void)
 {
- double d = get_and_check_float(1, "log10");
+ double d = lua_check_number(1, "log10");
  lua_pushnumber (log10(d));
 }
 
 
 static void math_exp (void)
 {
- double d = get_and_check_float(1, "exp");
+ double d = lua_check_number(1, "exp");
  lua_pushnumber (exp(d));
 }
 
 static void math_deg (void)
 {
- float d = get_and_check_float(1, "deg");
+ float d = lua_check_number(1, "deg");
  lua_pushnumber (d*180./PI);
 }
 
 static void math_rad (void)
 {
- float d = get_and_check_float(1, "rad");
+ float d = lua_check_number(1, "rad");
  lua_pushnumber (d/180.*PI);
 }
 
diff --git a/strlib.c b/strlib.c
index 12e696a2..12f9dcbf 100644
--- a/strlib.c
+++ b/strlib.c
@@ -3,7 +3,7 @@
 ** String library to LUA
 */
 
-char *rcs_strlib="$Id: strlib.c,v 1.12 1995/02/06 19:37:51 roberto Exp $";
+char *rcs_strlib="$Id: strlib.c,v 1.13 1995/10/09 12:49:21 roberto Exp roberto $";
 
 #include <string.h>
 #include <stdio.h>
@@ -14,27 +14,27 @@ char *rcs_strlib="$Id: strlib.c,v 1.12 1995/02/06 19:37:51 roberto Exp $";
 #include "lualib.h"
 
 
-static void str_error(char *funcname)
+void lua_arg_error(char *funcname)
 {
-  char buff[250];
+  char buff[100];
   sprintf(buff, "incorrect arguments to function `%s'", funcname);
   lua_error(buff);
 }
 
-static char *check_and_get_string (int numArg, char *funcname)
+char *lua_check_string (int numArg, char *funcname)
 {
   lua_Object o = lua_getparam(numArg);
   if (!(lua_isstring(o) || lua_isnumber(o)))
-    str_error(funcname);
+    lua_arg_error(funcname);
   return lua_getstring(o);
 }
 
-static int check_and_get_int (int numArg, char *funcname)
+float lua_check_number (int numArg, char *funcname)
 {
   lua_Object o = lua_getparam(numArg);
   if (!lua_isnumber(o))
-    str_error(funcname);
-  return (int)lua_getnumber(o);
+    lua_arg_error(funcname);
+  return lua_getnumber(o);
 }
 
 static char *newstring (char *s)
@@ -54,17 +54,17 @@ static char *newstring (char *s)
 */
 static void str_find (void)
 {
- char *s1 = check_and_get_string(1, "strfind");
- char *s2 = check_and_get_string(2, "strfind");
+ char *s1 = lua_check_string(1, "strfind");
+ char *s2 = lua_check_string(2, "strfind");
  int init = (lua_getparam(3) == LUA_NOOBJECT) ? 0 :
-                                 check_and_get_int(3, "strfind")-1;
+                                 (int)lua_check_number(3, "strfind")-1;
  char *f = strstr(s1+init,s2);
  if (f != NULL)
  {
   int pos = f-s1+1;
   if (lua_getparam (4) == LUA_NOOBJECT)
    lua_pushnumber (pos);
-  else if (check_and_get_int(4, "strfind") >= pos+strlen(s2)-1)
+  else if ((int)lua_check_number(4, "strfind") >= pos+strlen(s2)-1)
    lua_pushnumber (pos);
   else
    lua_pushnil();
@@ -80,7 +80,7 @@ static void str_find (void)
 */
 static void str_len (void)
 {
- char *s = check_and_get_string(1, "strlen");
+ char *s = lua_check_string(1, "strlen");
  lua_pushnumber(strlen(s));
 }
 
@@ -92,10 +92,10 @@ static void str_len (void)
 */
 static void str_sub (void)
 {
- char *s = check_and_get_string(1, "strsub");
- int start = check_and_get_int(2, "strsub");
+ char *s = lua_check_string(1, "strsub");
+ int start = (int)lua_check_number(2, "strsub");
  int end = (lua_getparam(3) == LUA_NOOBJECT) ? strlen(s) :
-                                    check_and_get_int(3, "strsub");
+                                    (int)lua_check_number(3, "strsub");
  if (end < start || start < 1 || end > strlen(s))
   lua_pushliteral("");
  else
@@ -114,7 +114,7 @@ typedef int (*strfunc)(int s);
 static void str_apply (strfunc f, char *funcname)
 {
  char *s, *c;
- c = s = newstring(check_and_get_string(1, funcname));
+ c = s = newstring(lua_check_string(1, funcname));
  while (*c != 0)
  {
   *c = f(*c);
@@ -150,12 +150,12 @@ static void str_upper (void)
 */
 static void str_ascii (void)
 {
-  char *s = check_and_get_string(1, "ascii");
+  char *s = lua_check_string(1, "ascii");
   lua_Object o2 = lua_getparam(2);
   int pos;
-  pos = (o2 == LUA_NOOBJECT) ? 0 : check_and_get_int(2, "ascii")-1;
+  pos = (o2 == LUA_NOOBJECT) ? 0 : (int)lua_check_number(2, "ascii")-1;
   if (pos<0 || pos>=strlen(s))
-    str_error("ascii");
+    lua_arg_error("ascii");
   lua_pushnumber(s[pos]);
 }
 
@@ -171,7 +171,7 @@ static void str_int2str (void)
   {
     if (i > maxparams)
       lua_error("too many parameters to function `int2str'");
-    s[i-1] = check_and_get_int(i, "int2str");
+    s[i-1] = (int)lua_check_number(i, "int2str");
   }
   s[i-1] = 0;
   lua_pushstring(s);