diff --git a/c/external.c b/c/external.c
index b001048..51e3e4e 100644
--- a/c/external.c
+++ b/c/external.c
@@ -473,12 +473,12 @@ s48_raise_scheme_exception(long why, long nargs, ...)
 /* Specific exceptions */
 
 void
-s48_raise_argtype_error(s48_value value) {
+s48_raise_argument_type_error(s48_value value) {
   s48_raise_scheme_exception(S48_EXCEPTION_WRONG_TYPE_ARGUMENT, 1, value);
 }
 
 void
-s48_raise_argnumber_error(s48_value value, s48_value min, s48_value max) {
+s48_raise_argument_number_error(s48_value value, s48_value min, s48_value max) {
   s48_raise_scheme_exception(S48_EXCEPTION_WRONG_NUMBER_OF_ARGUMENTS,
 			     3, value, min, max);
 }
@@ -582,7 +582,7 @@ long
 s48_stob_length(s48_value thing, int type)
 {
   if (!(S48_STOB_P(thing) && (S48_STOB_TYPE(thing) == type)))
-    s48_raise_argtype_error(thing);
+    s48_raise_argument_type_error(thing);
   
   return S48_STOB_DESCRIPTOR_LENGTH(thing);
 }
@@ -591,7 +591,7 @@ long
 s48_stob_byte_length(s48_value thing, int type)
 {
   if (!(S48_STOB_P(thing) && (S48_STOB_TYPE(thing) == type)))
-    s48_raise_argtype_error(thing);
+    s48_raise_argument_type_error(thing);
 
   if (type == S48_STOBTYPE_STRING)
     return S48_STOB_BYTE_LENGTH(thing) - 1;
@@ -605,7 +605,7 @@ s48_stob_ref(s48_value thing, int type, long offset)
   long length;
 
   if (!(S48_STOB_P(thing) && (S48_STOB_TYPE(thing) == type)))
-    s48_raise_argtype_error(thing);
+    s48_raise_argument_type_error(thing);
 
   length = S48_STOB_DESCRIPTOR_LENGTH(thing);
 
@@ -625,7 +625,7 @@ s48_stob_set(s48_value thing, int type, long offset, s48_value value)
   if (!(S48_STOB_P(thing) &&
 	(S48_STOB_TYPE(thing) == type) &&
 	!S48_STOB_IMMUTABLEP(thing)))
-    s48_raise_argtype_error(thing);
+    s48_raise_argument_type_error(thing);
   
   length = S48_STOB_DESCRIPTOR_LENGTH(thing);
 
@@ -643,7 +643,7 @@ s48_stob_byte_ref(s48_value thing, int type, long offset)
   long length;
 
   if (!(S48_STOB_P(thing) && (S48_STOB_TYPE(thing) == type)))
-    s48_raise_argtype_error(thing);
+    s48_raise_argument_type_error(thing);
   
   length = (type == S48_STOBTYPE_STRING) ?
            S48_STOB_BYTE_LENGTH(thing) - 1 :
@@ -663,7 +663,7 @@ s48_stob_byte_set(s48_value thing, int type, long offset, char value)
   long length;
 
   if (!(S48_STOB_P(thing) && (S48_STOB_TYPE(thing) == type)))
-    s48_raise_argtype_error(thing);
+    s48_raise_argument_type_error(thing);
   
   length = (type == S48_STOBTYPE_STRING) ?
            S48_STOB_BYTE_LENGTH(thing) - 1 :
@@ -698,7 +698,7 @@ s48_value
 s48_enter_fixnum(long value)
 {
   if (value < S48_MIN_FIXNUM_VALUE || S48_MAX_FIXNUM_VALUE < value)
-    s48_raise_argtype_error(s48_enter_integer(value));
+    s48_raise_argument_type_error(s48_enter_integer(value));
 
   return S48_UNSAFE_ENTER_FIXNUM(value);
 }
@@ -707,7 +707,7 @@ long
 s48_extract_fixnum(s48_value value)
 {
   if (! S48_FIXNUM_P(value))
-    s48_raise_argtype_error(value);
+    s48_raise_argument_type_error(value);
   
   return S48_UNSAFE_EXTRACT_FIXNUM(value);
 }
@@ -786,7 +786,7 @@ s48_extract_integer(s48_value value)
     S48_GC_UNPROTECT();
 
     if (stuff == S48_FALSE)
-      s48_raise_argtype_error(value);
+      s48_raise_argument_type_error(value);
 
     /* The first VECTOR_REF does the type checking for the rest. */
     {
@@ -797,7 +797,7 @@ s48_extract_integer(s48_value value)
       
       if ((! S48_FIXNUM_P(boxed_high)) ||
 	  high > (pos_p ? 0x7FFF : 0x8000))
-	s48_raise_argtype_error(value);
+	s48_raise_argument_type_error(value);
       
       {
       long magnitude = ((- high) << 16) - low;
@@ -814,7 +814,7 @@ s48_extract_unsigned_integer(s48_value value)
   if (S48_FIXNUM_P(value)){
     temp = S48_UNSAFE_EXTRACT_FIXNUM(value);
     if (temp < 0)
-      s48_raise_argtype_error(value);
+      s48_raise_argument_type_error(value);
     else return (unsigned long) temp;
   }
   else {
@@ -832,7 +832,7 @@ s48_extract_unsigned_integer(s48_value value)
     S48_GC_UNPROTECT();
 
     if (stuff == S48_FALSE)
-      s48_raise_argtype_error(value);
+      s48_raise_argument_type_error(value);
 
     /* The first VECTOR_REF does the type checking for the rest. */
     {
@@ -844,7 +844,7 @@ s48_extract_unsigned_integer(s48_value value)
       if ((!pos_p) || 
 	  (! S48_FIXNUM_P(boxed_high)) ||
 	  (high >  0xFFFF)) 
-	s48_raise_argtype_error(value);
+	s48_raise_argument_type_error(value);
       else return ((((unsigned long) high) << 16) + low);
     }
   }
@@ -869,7 +869,7 @@ double
 s48_extract_double(s48_value s48_double)
 {
   if (! S48_DOUBLE_P(s48_double))
-    s48_raise_argtype_error(s48_double);
+    s48_raise_argument_type_error(s48_double);
   
   return S48_UNSAFE_EXTRACT_DOUBLE(s48_double);
 }
@@ -889,7 +889,7 @@ unsigned char
 s48_extract_char(s48_value a_char)
 {
   if (! S48_CHAR_P(a_char))
-    s48_raise_argtype_error(a_char);
+    s48_raise_argument_type_error(a_char);
   
   return S48_UNSAFE_EXTRACT_CHAR(a_char);
 }
@@ -1063,7 +1063,7 @@ s48_check_record_type(s48_value record, s48_value type_binding)
   if ((! S48_RECORD_P(record)) ||
       (S48_UNSAFE_SHARED_BINDING_REF(type_binding) !=
        S48_UNSAFE_RECORD_REF(record, -1)))
-    s48_raise_argtype_error(record);
+    s48_raise_argument_type_error(record);
 }    
 
 long
diff --git a/c/scheme48.h b/c/scheme48.h
index 2035878..5b9411a 100644
--- a/c/scheme48.h
+++ b/c/scheme48.h
@@ -188,9 +188,10 @@ extern void *		s48_value_pointer(s48_value);
 /* Exceptions */
 
 extern void s48_raise_scheme_exception(long type, long nargs, ...);
-extern void s48_raise_argtype_error(s48_value value);
-extern void s48_raise_argnumber_error(s48_value value,
-				  s48_value min, s48_value max);
+extern void s48_raise_argument_type_error(s48_value value);
+extern void s48_raise_argument_number_error(s48_value value,
+					    s48_value min,
+					    s48_value max);
 extern void s48_raise_range_error(s48_value value,
 			      s48_value min, s48_value max);
 extern void s48_raise_closed_channel_error();
@@ -211,17 +212,22 @@ extern void s48_raise_out_of_memory_error();
 
 /* Type checking */
 
-#define S48_CHECK_PAIR(v) do { if (!S48_PAIR_P(v)) s48_raise_argtype_error(v); } while (0)
-#define S48_CHECK_FIXNUM(v) do { if (!S48_FIXNUM_P(v)) s48_raise_argtype_error(v); } while (0)
-#define S48_CHECK_STRING(v) do { if (!S48_STRING_P(v)) s48_raise_argtype_error(v); } while (0)
-#define S48_CHECK_BYTE_VECTOR(v) do { if (!S48_BYTE_VECTOR_P(v)) s48_raise_argtype_error(v); } while (0)
-#define S48_CHECK_CHANNEL(v) do { if (!S48_CHANNEL_P(v)) s48_raise_argtype_error(v); } while (0)
-#define S48_CHECK_RECORD(v) do { if (!S48_RECORD_P(v)) s48_raise_argtype_error(v); } while (0)
-#define S48_CHECK_VALUE(v) do { if (!S48_BYTE_VECTOR_P(v)) s48_raise_argtype_error(v); } while (0)
-#define S48_CHECK_EXPORT_BINDING(v) do { if (!S48_EXPORT_BINDING_P(v)) s48_raise_argtype_error(v); } while (0)
+#define S48_CHECK_PAIR(v) do { if (!S48_PAIR_P(v)) s48_raise_argument_type_error(v); } while (0)
+#define S48_CHECK_FIXNUM(v) do { if (!S48_FIXNUM_P(v)) s48_raise_argument_type_error(v); } while (0)
+#define S48_CHECK_STRING(v) do { if (!S48_STRING_P(v)) s48_raise_argument_type_error(v); } while (0)
+#define S48_CHECK_BYTE_VECTOR(v) do { if (!S48_BYTE_VECTOR_P(v)) s48_raise_argument_type_error(v); } while (0)
+#define S48_CHECK_CHANNEL(v) do { if (!S48_CHANNEL_P(v)) s48_raise_argument_type_error(v); } while (0)
+#define S48_CHECK_RECORD(v) do { if (!S48_RECORD_P(v)) s48_raise_argument_type_error(v); } while (0)
+#define S48_CHECK_VALUE(v) do { if (!S48_BYTE_VECTOR_P(v)) s48_raise_argument_type_error(v); } while (0)
+#define S48_CHECK_EXPORT_BINDING(v) do { if (!S48_EXPORT_BINDING_P(v)) s48_raise_argument_type_error(v); } while (0)
 
 #define S48_VALUE_P(v) (S48_BYTE_VECTOR_P(v))
 
+#define S48_TRUE_P(v) ((v) == S48_TRUE)
+#define S48_FALSE_P(v) ((v) == S48_FALSE)
+#define S48_EXTRACT_BOOLEAN(v) ((v) != S48_FALSE)
+#define S48_ENTER_BOOLEAN(v) ((v) ? S48_TRUE : S48_FALSE)
+
 extern void s48_check_record_type(s48_value record, s48_value type_binding);
 
 #define S48_SHARED_BINDING_CHECK(binding)					\
@@ -262,8 +268,8 @@ extern void s48_check_record_type(s48_value record, s48_value type_binding);
 #define S48_ADDRESS_AFTER_HEADER(x, type) ((type *)((x) - S48_STOB_TAG))
 #define S48_STOB_REF(x, i) (S48_ADDRESS_AFTER_HEADER(x, s48_value)[i])
 #define S48_STOB_BYTE_REF(x, i) (((char *)S48_ADDRESS_AFTER_HEADER(x, s48_value))[i])
-#define S48_STOB_SET(x, i, v) do { s48_value __stob_set_x = (x); long __stob_set_i = (i); s48_value __stob_set_v = (v); if (S48_STOB_IMMUTABLEP(__stob_set_x)) s48_raise_argtype_error(__stob_set_x); else { S48_WRITE_BARRIER((__stob_set_x), (char *) (&S48_STOB_REF((__stob_set_x), (__stob_set_i))),(__stob_set_v)); *(&S48_STOB_REF((__stob_set_x), (__stob_set_i))) = (__stob_set_v); } } while (0)
-#define S48_STOB_BYTE_SET(x, i, v) do { s48_value __stob_set_x = (x); long __stob_set_i = (i); char __stob_set_v = (v); if (S48_STOB_IMMUTABLEP(__stob_set_x)) s48_raise_argtype_error(__stob_set_x); else *(&S48_STOB_BYTE_REF((__stob_set_x), (__stob_set_i))) = (__stob_set_v); } while (0)
+#define S48_STOB_SET(x, i, v) do { s48_value __stob_set_x = (x); long __stob_set_i = (i); s48_value __stob_set_v = (v); if (S48_STOB_IMMUTABLEP(__stob_set_x)) s48_raise_argument_type_error(__stob_set_x); else { S48_WRITE_BARRIER((__stob_set_x), (char *) (&S48_STOB_REF((__stob_set_x), (__stob_set_i))),(__stob_set_v)); *(&S48_STOB_REF((__stob_set_x), (__stob_set_i))) = (__stob_set_v); } } while (0)
+#define S48_STOB_BYTE_SET(x, i, v) do { s48_value __stob_set_x = (x); long __stob_set_i = (i); char __stob_set_v = (v); if (S48_STOB_IMMUTABLEP(__stob_set_x)) s48_raise_argument_type_error(__stob_set_x); else *(&S48_STOB_BYTE_REF((__stob_set_x), (__stob_set_i))) = (__stob_set_v); } while (0)
 #define S48_STOB_TYPE(x)   ((S48_STOB_HEADER(x)>>2)&31)
 #define S48_STOB_HEADER(x) (S48_STOB_REF((x),-1))
 #define S48_STOB_ADDRESS(x) (&(S48_STOB_HEADER(x)))
diff --git a/c/scheme48.h.in b/c/scheme48.h.in
index 316c8e1..ed74cea 100644
--- a/c/scheme48.h.in
+++ b/c/scheme48.h.in
@@ -182,9 +182,10 @@ extern void *		s48_value_pointer(s48_value);
 /* Exceptions */
 
 extern void s48_raise_scheme_exception(long type, long nargs, ...);
-extern void s48_raise_argtype_error(s48_value value);
-extern void s48_raise_argnumber_error(s48_value value,
-				  s48_value min, s48_value max);
+extern void s48_raise_argument_type_error(s48_value value);
+extern void s48_raise_argument_number_error(s48_value value,
+					    s48_value min,
+					    s48_value max);
 extern void s48_raise_range_error(s48_value value,
 			      s48_value min, s48_value max);
 extern void s48_raise_closed_channel_error();
@@ -205,17 +206,22 @@ extern void s48_raise_out_of_memory_error();
 
 /* Type checking */
 
-#define S48_CHECK_PAIR(v) do { if (!S48_PAIR_P(v)) s48_raise_argtype_error(v); } while (0)
-#define S48_CHECK_FIXNUM(v) do { if (!S48_FIXNUM_P(v)) s48_raise_argtype_error(v); } while (0)
-#define S48_CHECK_STRING(v) do { if (!S48_STRING_P(v)) s48_raise_argtype_error(v); } while (0)
-#define S48_CHECK_BYTE_VECTOR(v) do { if (!S48_BYTE_VECTOR_P(v)) s48_raise_argtype_error(v); } while (0)
-#define S48_CHECK_CHANNEL(v) do { if (!S48_CHANNEL_P(v)) s48_raise_argtype_error(v); } while (0)
-#define S48_CHECK_RECORD(v) do { if (!S48_RECORD_P(v)) s48_raise_argtype_error(v); } while (0)
-#define S48_CHECK_VALUE(v) do { if (!S48_BYTE_VECTOR_P(v)) s48_raise_argtype_error(v); } while (0)
-#define S48_CHECK_EXPORT_BINDING(v) do { if (!S48_EXPORT_BINDING_P(v)) s48_raise_argtype_error(v); } while (0)
+#define S48_CHECK_PAIR(v) do { if (!S48_PAIR_P(v)) s48_raise_argument_type_error(v); } while (0)
+#define S48_CHECK_FIXNUM(v) do { if (!S48_FIXNUM_P(v)) s48_raise_argument_type_error(v); } while (0)
+#define S48_CHECK_STRING(v) do { if (!S48_STRING_P(v)) s48_raise_argument_type_error(v); } while (0)
+#define S48_CHECK_BYTE_VECTOR(v) do { if (!S48_BYTE_VECTOR_P(v)) s48_raise_argument_type_error(v); } while (0)
+#define S48_CHECK_CHANNEL(v) do { if (!S48_CHANNEL_P(v)) s48_raise_argument_type_error(v); } while (0)
+#define S48_CHECK_RECORD(v) do { if (!S48_RECORD_P(v)) s48_raise_argument_type_error(v); } while (0)
+#define S48_CHECK_VALUE(v) do { if (!S48_BYTE_VECTOR_P(v)) s48_raise_argument_type_error(v); } while (0)
+#define S48_CHECK_EXPORT_BINDING(v) do { if (!S48_EXPORT_BINDING_P(v)) s48_raise_argument_type_error(v); } while (0)
 
 #define S48_VALUE_P(v) (S48_BYTE_VECTOR_P(v))
 
+#define S48_TRUE_P(v) ((v) == S48_TRUE)
+#define S48_FALSE_P(v) ((v) == S48_FALSE)
+#define S48_EXTRACT_BOOLEAN(v) ((v) != S48_FALSE)
+#define S48_ENTER_BOOLEAN(v) ((v) ? S48_TRUE : S48_FALSE)
+
 extern void s48_check_record_type(s48_value record, s48_value type_binding);
 
 #define S48_SHARED_BINDING_CHECK(binding)					\
diff --git a/scheme/link/generate-c-header.scm b/scheme/link/generate-c-header.scm
index 122ffa9..69112b0 100644
--- a/scheme/link/generate-c-header.scm
+++ b/scheme/link/generate-c-header.scm
@@ -111,7 +111,7 @@
 	       "long __stob_set_i = (i); "
 	       "s48_value __stob_set_v = (v); "
 	       "if (S48_STOB_IMMUTABLEP(__stob_set_x)) "
-	       "s48_raise_argtype_error(__stob_set_x); "
+	       "s48_raise_argument_type_error(__stob_set_x); "
 	       "else { "
 	       "S48_WRITE_BARRIER((__stob_set_x), "
 	       "(char *) (&S48_STOB_REF((__stob_set_x), (__stob_set_i))),"
@@ -126,7 +126,7 @@
 	       "long __stob_set_i = (i); "
 	       "char __stob_set_v = (v); "
 	       "if (S48_STOB_IMMUTABLEP(__stob_set_x)) "
-	       "s48_raise_argtype_error(__stob_set_x); "
+	       "s48_raise_argument_type_error(__stob_set_x); "
 	       "else "
 	       "*(&S48_STOB_BYTE_REF((__stob_set_x), (__stob_set_i))) = (__stob_set_v); "
 	       "} while (0)"))
diff --git a/scsh/network1.c b/scsh/network1.c
index 7206708..2472c80 100644
--- a/scsh/network1.c
+++ b/scsh/network1.c
@@ -70,7 +70,7 @@ s48_value scheme_bind(s48_value sock, s48_value family, s48_value scheme_name)
 	return S48_UNSPECIFIC;
       }
     default:
-	s48_raise_argtype_error (family);	
+	s48_raise_argument_type_error (family);	
     }
 }
 
@@ -140,7 +140,7 @@ s48_value scheme_connect(s48_value sock, s48_value family, s48_value scheme_name
 	
       }
     default: 
-      s48_raise_argtype_error (family);	/* error unknown address family */ 
+      s48_raise_argument_type_error (family);	/* error unknown address family */ 
     } 
 }
 /*-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-*/
@@ -208,7 +208,7 @@ s48_value scheme_accept(s48_value sockfd_tagged, s48_value family)
 	break;
       }
     default:
-      s48_raise_argtype_error (family);	    /* error unknown address family */
+      s48_raise_argument_type_error (family);	    /* error unknown address family */
     }
 }
 
@@ -242,7 +242,7 @@ s48_value scheme_peer_name(s48_value sock, s48_value family)
 	break;
       }
     default:
-      s48_raise_argtype_error (family);	/* error unknown address family */
+      s48_raise_argument_type_error (family);	/* error unknown address family */
     }
 }
 /*-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-*/
@@ -274,7 +274,7 @@ s48_value scheme_socket_name(s48_value sock, s48_value family)
 	break;
       }
     default:
-      s48_raise_argtype_error (family);	/* error unknown address family */
+      s48_raise_argument_type_error (family);	/* error unknown address family */
     }
 }
 
@@ -383,7 +383,7 @@ s48_value send_substring(s48_value scm_sockfd,
       break;
       }
     default:
-      s48_raise_argtype_error (s48_extract_fixnum (scm_family));	
+      s48_raise_argument_type_error (s48_extract_fixnum (scm_family));	
       /* error unknown address family */
     }
   
diff --git a/scsh/syscalls1.c b/scsh/syscalls1.c
index a52bb84..3cc5243 100644
--- a/scsh/syscalls1.c
+++ b/scsh/syscalls1.c
@@ -862,7 +862,7 @@ s48_value errno_msg(s48_value sch_i)
 #endif
     char *sys_errlist[]; 
   extern int sys_nerr;
-  return ( i < 0 || i > sys_nerr ) ? s48_raise_argtype_error(sch_i)
+  return ( i < 0 || i > sys_nerr ) ? s48_raise_argument_type_error(sch_i)
 	: s48_enter_string (sys_errlist[i]);
 #endif /* !HAVE_STRERROR */
 }