auto import from //depot/cupcake/@135843
diff --git a/sh/arith.c b/sh/arith.c
new file mode 100644
index 0000000..f8f92a9
--- /dev/null
+++ b/sh/arith.c
@@ -0,0 +1,1587 @@
+/* A Bison parser, made by GNU Bison 1.875d.  */
+
+/* Skeleton parser for Yacc-like parsing with Bison,
+   Copyright (C) 1984, 1989, 1990, 2000, 2001, 2002, 2003, 2004 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.  */
+
+/* As a special exception, when this file is copied by Bison into a
+   Bison output file, you may use that output file without restriction.
+   This special exception was added by the Free Software Foundation
+   in version 1.24 of Bison.  */
+
+/* Written by Richard Stallman by simplifying the original so called
+   ``semantic'' parser.  */
+
+/* All symbols defined below should begin with yy or YY, to avoid
+   infringing on user name space.  This should be done even for local
+   variables, as they might otherwise be expanded by user macros.
+   There are some unavoidable exceptions within include files to
+   define necessary library symbols; they are noted "INFRINGES ON
+   USER NAME SPACE" below.  */
+
+/* Identify Bison output.  */
+#define YYBISON 1
+
+/* Skeleton name.  */
+#define YYSKELETON_NAME "yacc.c"
+
+/* Pure parsers.  */
+#define YYPURE 0
+
+/* Using locations.  */
+#define YYLSP_NEEDED 0
+
+
+
+/* Tokens.  */
+#ifndef YYTOKENTYPE
+# define YYTOKENTYPE
+   /* Put the tokens into the symbol table, so that GDB and other debuggers
+      know about them.  */
+   enum yytokentype {
+     ARITH_NUM = 258,
+     ARITH_LPAREN = 259,
+     ARITH_RPAREN = 260,
+     ARITH_OR = 261,
+     ARITH_AND = 262,
+     ARITH_BOR = 263,
+     ARITH_BXOR = 264,
+     ARITH_BAND = 265,
+     ARITH_NE = 266,
+     ARITH_EQ = 267,
+     ARITH_LE = 268,
+     ARITH_GE = 269,
+     ARITH_GT = 270,
+     ARITH_LT = 271,
+     ARITH_RSHIFT = 272,
+     ARITH_LSHIFT = 273,
+     ARITH_SUB = 274,
+     ARITH_ADD = 275,
+     ARITH_REM = 276,
+     ARITH_DIV = 277,
+     ARITH_MUL = 278,
+     ARITH_BNOT = 279,
+     ARITH_NOT = 280,
+     ARITH_UNARYPLUS = 281,
+     ARITH_UNARYMINUS = 282
+   };
+#endif
+#define ARITH_NUM 258
+#define ARITH_LPAREN 259
+#define ARITH_RPAREN 260
+#define ARITH_OR 261
+#define ARITH_AND 262
+#define ARITH_BOR 263
+#define ARITH_BXOR 264
+#define ARITH_BAND 265
+#define ARITH_NE 266
+#define ARITH_EQ 267
+#define ARITH_LE 268
+#define ARITH_GE 269
+#define ARITH_GT 270
+#define ARITH_LT 271
+#define ARITH_RSHIFT 272
+#define ARITH_LSHIFT 273
+#define ARITH_SUB 274
+#define ARITH_ADD 275
+#define ARITH_REM 276
+#define ARITH_DIV 277
+#define ARITH_MUL 278
+#define ARITH_BNOT 279
+#define ARITH_NOT 280
+#define ARITH_UNARYPLUS 281
+#define ARITH_UNARYMINUS 282
+
+
+
+
+/* Copy the first part of user declarations.  */
+#line 1 "arith.y"
+
+/*	$NetBSD: arith.y,v 1.17 2003/09/17 17:33:36 jmmv Exp $	*/
+
+/*-
+ * Copyright (c) 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Kenneth Almquist.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+#ifndef lint
+#if 0
+static char sccsid[] = "@(#)arith.y	8.3 (Berkeley) 5/4/95";
+#else
+__RCSID("$NetBSD: arith.y,v 1.17 2003/09/17 17:33:36 jmmv Exp $");
+#endif
+#endif /* not lint */
+
+#include <stdlib.h>
+#include "expand.h"
+#include "shell.h"
+#include "error.h"
+#include "output.h"
+#include "memalloc.h"
+
+const char *arith_buf, *arith_startbuf;
+
+void yyerror(const char *);
+#ifdef TESTARITH
+int main(int , char *[]);
+int error(char *);
+#endif
+
+
+
+/* Enabling traces.  */
+#ifndef YYDEBUG
+# define YYDEBUG 0
+#endif
+
+/* Enabling verbose error messages.  */
+#ifdef YYERROR_VERBOSE
+# undef YYERROR_VERBOSE
+# define YYERROR_VERBOSE 1
+#else
+# define YYERROR_VERBOSE 0
+#endif
+
+#if ! defined (YYSTYPE) && ! defined (YYSTYPE_IS_DECLARED)
+typedef int YYSTYPE;
+# define yystype YYSTYPE /* obsolescent; will be withdrawn */
+# define YYSTYPE_IS_DECLARED 1
+# define YYSTYPE_IS_TRIVIAL 1
+#endif
+
+
+
+/* Copy the second part of user declarations.  */
+
+
+/* Line 214 of yacc.c.  */
+#line 202 "arith.c"
+
+#if ! defined (yyoverflow) || YYERROR_VERBOSE
+
+# ifndef YYFREE
+#  define YYFREE free
+# endif
+# ifndef YYMALLOC
+#  define YYMALLOC malloc
+# endif
+
+/* The parser invokes alloca or malloc; define the necessary symbols.  */
+
+# ifdef YYSTACK_USE_ALLOCA
+#  if YYSTACK_USE_ALLOCA
+#   define YYSTACK_ALLOC alloca
+#  endif
+# else
+#  if defined (alloca) || defined (_ALLOCA_H)
+#   define YYSTACK_ALLOC alloca
+#  else
+#   ifdef __GNUC__
+#    define YYSTACK_ALLOC __builtin_alloca
+#   endif
+#  endif
+# endif
+
+# ifdef YYSTACK_ALLOC
+   /* Pacify GCC's `empty if-body' warning. */
+#  define YYSTACK_FREE(Ptr) do { /* empty */; } while (0)
+# else
+#  if defined (__STDC__) || defined (__cplusplus)
+#   include <stdlib.h> /* INFRINGES ON USER NAME SPACE */
+#   define YYSIZE_T size_t
+#  endif
+#  define YYSTACK_ALLOC YYMALLOC
+#  define YYSTACK_FREE YYFREE
+# endif
+#endif /* ! defined (yyoverflow) || YYERROR_VERBOSE */
+
+
+#if (! defined (yyoverflow) \
+     && (! defined (__cplusplus) \
+	 || (defined (YYSTYPE_IS_TRIVIAL) && YYSTYPE_IS_TRIVIAL)))
+
+/* A type that is properly aligned for any stack member.  */
+union yyalloc
+{
+  short int yyss;
+  YYSTYPE yyvs;
+  };
+
+/* The size of the maximum gap between one aligned stack and the next.  */
+# define YYSTACK_GAP_MAXIMUM (sizeof (union yyalloc) - 1)
+
+/* The size of an array large to enough to hold all stacks, each with
+   N elements.  */
+# define YYSTACK_BYTES(N) \
+     ((N) * (sizeof (short int) + sizeof (YYSTYPE))			\
+      + YYSTACK_GAP_MAXIMUM)
+
+/* Copy COUNT objects from FROM to TO.  The source and destination do
+   not overlap.  */
+# ifndef YYCOPY
+#  if defined (__GNUC__) && 1 < __GNUC__
+#   define YYCOPY(To, From, Count) \
+      __builtin_memcpy (To, From, (Count) * sizeof (*(From)))
+#  else
+#   define YYCOPY(To, From, Count)		\
+      do					\
+	{					\
+	  register YYSIZE_T yyi;		\
+	  for (yyi = 0; yyi < (Count); yyi++)	\
+	    (To)[yyi] = (From)[yyi];		\
+	}					\
+      while (0)
+#  endif
+# endif
+
+/* Relocate STACK from its old location to the new one.  The
+   local variables YYSIZE and YYSTACKSIZE give the old and new number of
+   elements in the stack, and YYPTR gives the new location of the
+   stack.  Advance YYPTR to a properly aligned location for the next
+   stack.  */
+# define YYSTACK_RELOCATE(Stack)					\
+    do									\
+      {									\
+	YYSIZE_T yynewbytes;						\
+	YYCOPY (&yyptr->Stack, Stack, yysize);				\
+	Stack = &yyptr->Stack;						\
+	yynewbytes = yystacksize * sizeof (*Stack) + YYSTACK_GAP_MAXIMUM; \
+	yyptr += yynewbytes / sizeof (*yyptr);				\
+      }									\
+    while (0)
+
+#endif
+
+#if defined (__STDC__) || defined (__cplusplus)
+   typedef signed char yysigned_char;
+#else
+   typedef short int yysigned_char;
+#endif
+
+/* YYFINAL -- State number of the termination state. */
+#define YYFINAL  14
+/* YYLAST -- Last index in YYTABLE.  */
+#define YYLAST   170
+
+/* YYNTOKENS -- Number of terminals. */
+#define YYNTOKENS  28
+/* YYNNTS -- Number of nonterminals. */
+#define YYNNTS  3
+/* YYNRULES -- Number of rules. */
+#define YYNRULES  26
+/* YYNRULES -- Number of states. */
+#define YYNSTATES  52
+
+/* YYTRANSLATE(YYLEX) -- Bison symbol number corresponding to YYLEX.  */
+#define YYUNDEFTOK  2
+#define YYMAXUTOK   282
+
+#define YYTRANSLATE(YYX) 						\
+  ((unsigned int) (YYX) <= YYMAXUTOK ? yytranslate[YYX] : YYUNDEFTOK)
+
+/* YYTRANSLATE[YYLEX] -- Bison symbol number corresponding to YYLEX.  */
+static const unsigned char yytranslate[] =
+{
+       0,     2,     2,     2,     2,     2,     2,     2,     2,     2,
+       2,     2,     2,     2,     2,     2,     2,     2,     2,     2,
+       2,     2,     2,     2,     2,     2,     2,     2,     2,     2,
+       2,     2,     2,     2,     2,     2,     2,     2,     2,     2,
+       2,     2,     2,     2,     2,     2,     2,     2,     2,     2,
+       2,     2,     2,     2,     2,     2,     2,     2,     2,     2,
+       2,     2,     2,     2,     2,     2,     2,     2,     2,     2,
+       2,     2,     2,     2,     2,     2,     2,     2,     2,     2,
+       2,     2,     2,     2,     2,     2,     2,     2,     2,     2,
+       2,     2,     2,     2,     2,     2,     2,     2,     2,     2,
+       2,     2,     2,     2,     2,     2,     2,     2,     2,     2,
+       2,     2,     2,     2,     2,     2,     2,     2,     2,     2,
+       2,     2,     2,     2,     2,     2,     2,     2,     2,     2,
+       2,     2,     2,     2,     2,     2,     2,     2,     2,     2,
+       2,     2,     2,     2,     2,     2,     2,     2,     2,     2,
+       2,     2,     2,     2,     2,     2,     2,     2,     2,     2,
+       2,     2,     2,     2,     2,     2,     2,     2,     2,     2,
+       2,     2,     2,     2,     2,     2,     2,     2,     2,     2,
+       2,     2,     2,     2,     2,     2,     2,     2,     2,     2,
+       2,     2,     2,     2,     2,     2,     2,     2,     2,     2,
+       2,     2,     2,     2,     2,     2,     2,     2,     2,     2,
+       2,     2,     2,     2,     2,     2,     2,     2,     2,     2,
+       2,     2,     2,     2,     2,     2,     2,     2,     2,     2,
+       2,     2,     2,     2,     2,     2,     2,     2,     2,     2,
+       2,     2,     2,     2,     2,     2,     2,     2,     2,     2,
+       2,     2,     2,     2,     2,     2,     1,     2,     3,     4,
+       5,     6,     7,     8,     9,    10,    11,    12,    13,    14,
+      15,    16,    17,    18,    19,    20,    21,    22,    23,    24,
+      25,    26,    27
+};
+
+#if YYDEBUG
+/* YYPRHS[YYN] -- Index of the first RHS symbol of rule number YYN in
+   YYRHS.  */
+static const unsigned char yyprhs[] =
+{
+       0,     0,     3,     5,     9,    13,    17,    21,    25,    29,
+      33,    37,    41,    45,    49,    53,    57,    61,    65,    69,
+      73,    77,    81,    84,    87,    90,    93
+};
+
+/* YYRHS -- A `-1'-separated list of the rules' RHS. */
+static const yysigned_char yyrhs[] =
+{
+      29,     0,    -1,    30,    -1,     4,    30,     5,    -1,    30,
+       6,    30,    -1,    30,     7,    30,    -1,    30,     8,    30,
+      -1,    30,     9,    30,    -1,    30,    10,    30,    -1,    30,
+      12,    30,    -1,    30,    15,    30,    -1,    30,    14,    30,
+      -1,    30,    16,    30,    -1,    30,    13,    30,    -1,    30,
+      11,    30,    -1,    30,    18,    30,    -1,    30,    17,    30,
+      -1,    30,    20,    30,    -1,    30,    19,    30,    -1,    30,
+      23,    30,    -1,    30,    22,    30,    -1,    30,    21,    30,
+      -1,    25,    30,    -1,    24,    30,    -1,    19,    30,    -1,
+      20,    30,    -1,     3,    -1
+};
+
+/* YYRLINE[YYN] -- source line where rule number YYN was defined.  */
+static const unsigned char yyrline[] =
+{
+       0,    76,    76,    82,    83,    84,    85,    86,    87,    88,
+      89,    90,    91,    92,    93,    94,    95,    96,    97,    98,
+      99,   104,   109,   110,   111,   112,   113
+};
+#endif
+
+#if YYDEBUG || YYERROR_VERBOSE
+/* YYTNME[SYMBOL-NUM] -- String name of the symbol SYMBOL-NUM.
+   First, the terminals, then, starting at YYNTOKENS, nonterminals. */
+static const char *const yytname[] =
+{
+  "$end", "error", "$undefined", "ARITH_NUM", "ARITH_LPAREN",
+  "ARITH_RPAREN", "ARITH_OR", "ARITH_AND", "ARITH_BOR", "ARITH_BXOR",
+  "ARITH_BAND", "ARITH_NE", "ARITH_EQ", "ARITH_LE", "ARITH_GE", "ARITH_GT",
+  "ARITH_LT", "ARITH_RSHIFT", "ARITH_LSHIFT", "ARITH_SUB", "ARITH_ADD",
+  "ARITH_REM", "ARITH_DIV", "ARITH_MUL", "ARITH_BNOT", "ARITH_NOT",
+  "ARITH_UNARYPLUS", "ARITH_UNARYMINUS", "$accept", "exp", "expr", 0
+};
+#endif
+
+# ifdef YYPRINT
+/* YYTOKNUM[YYLEX-NUM] -- Internal token number corresponding to
+   token YYLEX-NUM.  */
+static const unsigned short int yytoknum[] =
+{
+       0,   256,   257,   258,   259,   260,   261,   262,   263,   264,
+     265,   266,   267,   268,   269,   270,   271,   272,   273,   274,
+     275,   276,   277,   278,   279,   280,   281,   282
+};
+# endif
+
+/* YYR1[YYN] -- Symbol number of symbol that rule YYN derives.  */
+static const unsigned char yyr1[] =
+{
+       0,    28,    29,    30,    30,    30,    30,    30,    30,    30,
+      30,    30,    30,    30,    30,    30,    30,    30,    30,    30,
+      30,    30,    30,    30,    30,    30,    30
+};
+
+/* YYR2[YYN] -- Number of symbols composing right hand side of rule YYN.  */
+static const unsigned char yyr2[] =
+{
+       0,     2,     1,     3,     3,     3,     3,     3,     3,     3,
+       3,     3,     3,     3,     3,     3,     3,     3,     3,     3,
+       3,     3,     2,     2,     2,     2,     1
+};
+
+/* YYDEFACT[STATE-NAME] -- Default rule to reduce with in state
+   STATE-NUM when YYTABLE doesn't specify something else to do.  Zero
+   means the default is an error.  */
+static const unsigned char yydefact[] =
+{
+       0,    26,     0,     0,     0,     0,     0,     0,     2,     0,
+      24,    25,    23,    22,     1,     0,     0,     0,     0,     0,
+       0,     0,     0,     0,     0,     0,     0,     0,     0,     0,
+       0,     0,     0,     3,     4,     5,     6,     7,     8,    14,
+       9,    13,    11,    10,    12,    16,    15,    18,    17,    21,
+      20,    19
+};
+
+/* YYDEFGOTO[NTERM-NUM]. */
+static const yysigned_char yydefgoto[] =
+{
+      -1,     7,     8
+};
+
+/* YYPACT[STATE-NUM] -- Index in YYTABLE of the portion describing
+   STATE-NUM.  */
+#define YYPACT_NINF -13
+static const short int yypact[] =
+{
+      28,   -13,    28,    28,    28,    28,    28,    12,    67,    49,
+     -13,   -13,   -13,   -13,   -13,    28,    28,    28,    28,    28,
+      28,    28,    28,    28,    28,    28,    28,    28,    28,    28,
+      28,    28,    28,   -13,    84,   100,   115,    23,   128,   139,
+     139,   -12,   -12,   -12,   -12,   144,   144,   147,   147,   -13,
+     -13,   -13
+};
+
+/* YYPGOTO[NTERM-NUM].  */
+static const yysigned_char yypgoto[] =
+{
+     -13,   -13,    -2
+};
+
+/* YYTABLE[YYPACT[STATE-NUM]].  What to do in state STATE-NUM.  If
+   positive, shift that token.  If negative, reduce the rule which
+   number is the opposite.  If zero, do what YYDEFACT says.
+   If YYTABLE_NINF, syntax error.  */
+#define YYTABLE_NINF -1
+static const unsigned char yytable[] =
+{
+       9,    10,    11,    12,    13,    26,    27,    28,    29,    30,
+      31,    32,    14,    34,    35,    36,    37,    38,    39,    40,
+      41,    42,    43,    44,    45,    46,    47,    48,    49,    50,
+      51,     1,     2,    19,    20,    21,    22,    23,    24,    25,
+      26,    27,    28,    29,    30,    31,    32,     3,     4,     0,
+       0,     0,     5,     6,    33,    15,    16,    17,    18,    19,
+      20,    21,    22,    23,    24,    25,    26,    27,    28,    29,
+      30,    31,    32,    15,    16,    17,    18,    19,    20,    21,
+      22,    23,    24,    25,    26,    27,    28,    29,    30,    31,
+      32,    16,    17,    18,    19,    20,    21,    22,    23,    24,
+      25,    26,    27,    28,    29,    30,    31,    32,    17,    18,
+      19,    20,    21,    22,    23,    24,    25,    26,    27,    28,
+      29,    30,    31,    32,    18,    19,    20,    21,    22,    23,
+      24,    25,    26,    27,    28,    29,    30,    31,    32,    20,
+      21,    22,    23,    24,    25,    26,    27,    28,    29,    30,
+      31,    32,    22,    23,    24,    25,    26,    27,    28,    29,
+      30,    31,    32,    28,    29,    30,    31,    32,    30,    31,
+      32
+};
+
+static const yysigned_char yycheck[] =
+{
+       2,     3,     4,     5,     6,    17,    18,    19,    20,    21,
+      22,    23,     0,    15,    16,    17,    18,    19,    20,    21,
+      22,    23,    24,    25,    26,    27,    28,    29,    30,    31,
+      32,     3,     4,    10,    11,    12,    13,    14,    15,    16,
+      17,    18,    19,    20,    21,    22,    23,    19,    20,    -1,
+      -1,    -1,    24,    25,     5,     6,     7,     8,     9,    10,
+      11,    12,    13,    14,    15,    16,    17,    18,    19,    20,
+      21,    22,    23,     6,     7,     8,     9,    10,    11,    12,
+      13,    14,    15,    16,    17,    18,    19,    20,    21,    22,
+      23,     7,     8,     9,    10,    11,    12,    13,    14,    15,
+      16,    17,    18,    19,    20,    21,    22,    23,     8,     9,
+      10,    11,    12,    13,    14,    15,    16,    17,    18,    19,
+      20,    21,    22,    23,     9,    10,    11,    12,    13,    14,
+      15,    16,    17,    18,    19,    20,    21,    22,    23,    11,
+      12,    13,    14,    15,    16,    17,    18,    19,    20,    21,
+      22,    23,    13,    14,    15,    16,    17,    18,    19,    20,
+      21,    22,    23,    19,    20,    21,    22,    23,    21,    22,
+      23
+};
+
+/* YYSTOS[STATE-NUM] -- The (internal number of the) accessing
+   symbol of state STATE-NUM.  */
+static const unsigned char yystos[] =
+{
+       0,     3,     4,    19,    20,    24,    25,    29,    30,    30,
+      30,    30,    30,    30,     0,     6,     7,     8,     9,    10,
+      11,    12,    13,    14,    15,    16,    17,    18,    19,    20,
+      21,    22,    23,     5,    30,    30,    30,    30,    30,    30,
+      30,    30,    30,    30,    30,    30,    30,    30,    30,    30,
+      30,    30
+};
+
+#if ! defined (YYSIZE_T) && defined (__SIZE_TYPE__)
+# define YYSIZE_T __SIZE_TYPE__
+#endif
+#if ! defined (YYSIZE_T) && defined (size_t)
+# define YYSIZE_T size_t
+#endif
+#if ! defined (YYSIZE_T)
+# if defined (__STDC__) || defined (__cplusplus)
+#  include <stddef.h> /* INFRINGES ON USER NAME SPACE */
+#  define YYSIZE_T size_t
+# endif
+#endif
+#if ! defined (YYSIZE_T)
+# define YYSIZE_T unsigned int
+#endif
+
+#define yyerrok		(yyerrstatus = 0)
+#define yyclearin	(yychar = YYEMPTY)
+#define YYEMPTY		(-2)
+#define YYEOF		0
+
+#define YYACCEPT	goto yyacceptlab
+#define YYABORT		goto yyabortlab
+#define YYERROR		goto yyerrorlab
+
+
+/* Like YYERROR except do call yyerror.  This remains here temporarily
+   to ease the transition to the new meaning of YYERROR, for GCC.
+   Once GCC version 2 has supplanted version 1, this can go.  */
+
+#define YYFAIL		goto yyerrlab
+
+#define YYRECOVERING()  (!!yyerrstatus)
+
+#define YYBACKUP(Token, Value)					\
+do								\
+  if (yychar == YYEMPTY && yylen == 1)				\
+    {								\
+      yychar = (Token);						\
+      yylval = (Value);						\
+      yytoken = YYTRANSLATE (yychar);				\
+      YYPOPSTACK;						\
+      goto yybackup;						\
+    }								\
+  else								\
+    { 								\
+      yyerror ("syntax error: cannot back up");\
+      YYERROR;							\
+    }								\
+while (0)
+
+#define YYTERROR	1
+#define YYERRCODE	256
+
+/* YYLLOC_DEFAULT -- Compute the default location (before the actions
+   are run).  */
+
+#ifndef YYLLOC_DEFAULT
+# define YYLLOC_DEFAULT(Current, Rhs, N)		\
+   ((Current).first_line   = (Rhs)[1].first_line,	\
+    (Current).first_column = (Rhs)[1].first_column,	\
+    (Current).last_line    = (Rhs)[N].last_line,	\
+    (Current).last_column  = (Rhs)[N].last_column)
+#endif
+
+/* YYLEX -- calling `yylex' with the right arguments.  */
+
+#ifdef YYLEX_PARAM
+# define YYLEX yylex (YYLEX_PARAM)
+#else
+# define YYLEX yylex ()
+#endif
+
+/* Enable debugging if requested.  */
+#if YYDEBUG
+
+# ifndef YYFPRINTF
+#  include <stdio.h> /* INFRINGES ON USER NAME SPACE */
+#  define YYFPRINTF fprintf
+# endif
+
+# define YYDPRINTF(Args)			\
+do {						\
+  if (yydebug)					\
+    YYFPRINTF Args;				\
+} while (0)
+
+# define YYDSYMPRINT(Args)			\
+do {						\
+  if (yydebug)					\
+    yysymprint Args;				\
+} while (0)
+
+# define YYDSYMPRINTF(Title, Token, Value, Location)		\
+do {								\
+  if (yydebug)							\
+    {								\
+      YYFPRINTF (stderr, "%s ", Title);				\
+      yysymprint (stderr, 					\
+                  Token, Value);	\
+      YYFPRINTF (stderr, "\n");					\
+    }								\
+} while (0)
+
+/*------------------------------------------------------------------.
+| yy_stack_print -- Print the state stack from its BOTTOM up to its |
+| TOP (included).                                                   |
+`------------------------------------------------------------------*/
+
+#if defined (__STDC__) || defined (__cplusplus)
+static void
+yy_stack_print (short int *bottom, short int *top)
+#else
+static void
+yy_stack_print (bottom, top)
+    short int *bottom;
+    short int *top;
+#endif
+{
+  YYFPRINTF (stderr, "Stack now");
+  for (/* Nothing. */; bottom <= top; ++bottom)
+    YYFPRINTF (stderr, " %d", *bottom);
+  YYFPRINTF (stderr, "\n");
+}
+
+# define YY_STACK_PRINT(Bottom, Top)				\
+do {								\
+  if (yydebug)							\
+    yy_stack_print ((Bottom), (Top));				\
+} while (0)
+
+
+/*------------------------------------------------.
+| Report that the YYRULE is going to be reduced.  |
+`------------------------------------------------*/
+
+#if defined (__STDC__) || defined (__cplusplus)
+static void
+yy_reduce_print (int yyrule)
+#else
+static void
+yy_reduce_print (yyrule)
+    int yyrule;
+#endif
+{
+  int yyi;
+  unsigned int yylno = yyrline[yyrule];
+  YYFPRINTF (stderr, "Reducing stack by rule %d (line %u), ",
+             yyrule - 1, yylno);
+  /* Print the symbols being reduced, and their result.  */
+  for (yyi = yyprhs[yyrule]; 0 <= yyrhs[yyi]; yyi++)
+    YYFPRINTF (stderr, "%s ", yytname [yyrhs[yyi]]);
+  YYFPRINTF (stderr, "-> %s\n", yytname [yyr1[yyrule]]);
+}
+
+# define YY_REDUCE_PRINT(Rule)		\
+do {					\
+  if (yydebug)				\
+    yy_reduce_print (Rule);		\
+} while (0)
+
+/* Nonzero means print parse trace.  It is left uninitialized so that
+   multiple parsers can coexist.  */
+int yydebug;
+#else /* !YYDEBUG */
+# define YYDPRINTF(Args)
+# define YYDSYMPRINT(Args)
+# define YYDSYMPRINTF(Title, Token, Value, Location)
+# define YY_STACK_PRINT(Bottom, Top)
+# define YY_REDUCE_PRINT(Rule)
+#endif /* !YYDEBUG */
+
+
+/* YYINITDEPTH -- initial size of the parser's stacks.  */
+#ifndef	YYINITDEPTH
+# define YYINITDEPTH 200
+#endif
+
+/* YYMAXDEPTH -- maximum size the stacks can grow to (effective only
+   if the built-in stack extension method is used).
+
+   Do not make this value too large; the results are undefined if
+   SIZE_MAX < YYSTACK_BYTES (YYMAXDEPTH)
+   evaluated with infinite-precision integer arithmetic.  */
+
+#if defined (YYMAXDEPTH) && YYMAXDEPTH == 0
+# undef YYMAXDEPTH
+#endif
+
+#ifndef YYMAXDEPTH
+# define YYMAXDEPTH 10000
+#endif
+
+
+
+#if YYERROR_VERBOSE
+
+# ifndef yystrlen
+#  if defined (__GLIBC__) && defined (_STRING_H)
+#   define yystrlen strlen
+#  else
+/* Return the length of YYSTR.  */
+static YYSIZE_T
+#   if defined (__STDC__) || defined (__cplusplus)
+yystrlen (const char *yystr)
+#   else
+yystrlen (yystr)
+     const char *yystr;
+#   endif
+{
+  register const char *yys = yystr;
+
+  while (*yys++ != '\0')
+    continue;
+
+  return yys - yystr - 1;
+}
+#  endif
+# endif
+
+# ifndef yystpcpy
+#  if defined (__GLIBC__) && defined (_STRING_H) && defined (_GNU_SOURCE)
+#   define yystpcpy stpcpy
+#  else
+/* Copy YYSRC to YYDEST, returning the address of the terminating '\0' in
+   YYDEST.  */
+static char *
+#   if defined (__STDC__) || defined (__cplusplus)
+yystpcpy (char *yydest, const char *yysrc)
+#   else
+yystpcpy (yydest, yysrc)
+     char *yydest;
+     const char *yysrc;
+#   endif
+{
+  register char *yyd = yydest;
+  register const char *yys = yysrc;
+
+  while ((*yyd++ = *yys++) != '\0')
+    continue;
+
+  return yyd - 1;
+}
+#  endif
+# endif
+
+#endif /* !YYERROR_VERBOSE */
+
+
+
+#if YYDEBUG
+/*--------------------------------.
+| Print this symbol on YYOUTPUT.  |
+`--------------------------------*/
+
+#if defined (__STDC__) || defined (__cplusplus)
+static void
+yysymprint (FILE *yyoutput, int yytype, YYSTYPE *yyvaluep)
+#else
+static void
+yysymprint (yyoutput, yytype, yyvaluep)
+    FILE *yyoutput;
+    int yytype;
+    YYSTYPE *yyvaluep;
+#endif
+{
+  /* Pacify ``unused variable'' warnings.  */
+  (void) yyvaluep;
+
+  if (yytype < YYNTOKENS)
+    {
+      YYFPRINTF (yyoutput, "token %s (", yytname[yytype]);
+# ifdef YYPRINT
+      YYPRINT (yyoutput, yytoknum[yytype], *yyvaluep);
+# endif
+    }
+  else
+    YYFPRINTF (yyoutput, "nterm %s (", yytname[yytype]);
+
+  switch (yytype)
+    {
+      default:
+        break;
+    }
+  YYFPRINTF (yyoutput, ")");
+}
+
+#endif /* ! YYDEBUG */
+/*-----------------------------------------------.
+| Release the memory associated to this symbol.  |
+`-----------------------------------------------*/
+
+#if defined (__STDC__) || defined (__cplusplus)
+static void
+yydestruct (int yytype, YYSTYPE *yyvaluep)
+#else
+static void
+yydestruct (yytype, yyvaluep)
+    int yytype;
+    YYSTYPE *yyvaluep;
+#endif
+{
+  /* Pacify ``unused variable'' warnings.  */
+  (void) yyvaluep;
+
+  switch (yytype)
+    {
+
+      default:
+        break;
+    }
+}
+
+
+/* Prevent warnings from -Wmissing-prototypes.  */
+
+#ifdef YYPARSE_PARAM
+# if defined (__STDC__) || defined (__cplusplus)
+int yyparse (void *YYPARSE_PARAM);
+# else
+int yyparse ();
+# endif
+#else /* ! YYPARSE_PARAM */
+#if defined (__STDC__) || defined (__cplusplus)
+int yyparse (void);
+#else
+int yyparse ();
+#endif
+#endif /* ! YYPARSE_PARAM */
+
+
+
+/* The lookahead symbol.  */
+int yychar;
+
+/* The semantic value of the lookahead symbol.  */
+YYSTYPE yylval;
+
+/* Number of syntax errors so far.  */
+int yynerrs;
+
+
+
+/*----------.
+| yyparse.  |
+`----------*/
+
+#ifdef YYPARSE_PARAM
+# if defined (__STDC__) || defined (__cplusplus)
+int yyparse (void *YYPARSE_PARAM)
+# else
+int yyparse (YYPARSE_PARAM)
+  void *YYPARSE_PARAM;
+# endif
+#else /* ! YYPARSE_PARAM */
+#if defined (__STDC__) || defined (__cplusplus)
+int
+yyparse (void)
+#else
+int
+yyparse ()
+
+#endif
+#endif
+{
+  
+  register int yystate;
+  register int yyn;
+  int yyresult;
+  /* Number of tokens to shift before error messages enabled.  */
+  int yyerrstatus;
+  /* Lookahead token as an internal (translated) token number.  */
+  int yytoken = 0;
+
+  /* Three stacks and their tools:
+     `yyss': related to states,
+     `yyvs': related to semantic values,
+     `yyls': related to locations.
+
+     Refer to the stacks thru separate pointers, to allow yyoverflow
+     to reallocate them elsewhere.  */
+
+  /* The state stack.  */
+  short int yyssa[YYINITDEPTH];
+  short int *yyss = yyssa;
+  register short int *yyssp;
+
+  /* The semantic value stack.  */
+  YYSTYPE yyvsa[YYINITDEPTH];
+  YYSTYPE *yyvs = yyvsa;
+  register YYSTYPE *yyvsp;
+
+
+
+#define YYPOPSTACK   (yyvsp--, yyssp--)
+
+  YYSIZE_T yystacksize = YYINITDEPTH;
+
+  /* The variables used to return semantic value and location from the
+     action routines.  */
+  YYSTYPE yyval;
+
+
+  /* When reducing, the number of symbols on the RHS of the reduced
+     rule.  */
+  int yylen;
+
+  YYDPRINTF ((stderr, "Starting parse\n"));
+
+  yystate = 0;
+  yyerrstatus = 0;
+  yynerrs = 0;
+  yychar = YYEMPTY;		/* Cause a token to be read.  */
+
+  /* Initialize stack pointers.
+     Waste one element of value and location stack
+     so that they stay on the same level as the state stack.
+     The wasted elements are never initialized.  */
+
+  yyssp = yyss;
+  yyvsp = yyvs;
+
+
+  goto yysetstate;
+
+/*------------------------------------------------------------.
+| yynewstate -- Push a new state, which is found in yystate.  |
+`------------------------------------------------------------*/
+ yynewstate:
+  /* In all cases, when you get here, the value and location stacks
+     have just been pushed. so pushing a state here evens the stacks.
+     */
+  yyssp++;
+
+ yysetstate:
+  *yyssp = yystate;
+
+  if (yyss + yystacksize - 1 <= yyssp)
+    {
+      /* Get the current used size of the three stacks, in elements.  */
+      YYSIZE_T yysize = yyssp - yyss + 1;
+
+#ifdef yyoverflow
+      {
+	/* Give user a chance to reallocate the stack. Use copies of
+	   these so that the &'s don't force the real ones into
+	   memory.  */
+	YYSTYPE *yyvs1 = yyvs;
+	short int *yyss1 = yyss;
+
+
+	/* Each stack pointer address is followed by the size of the
+	   data in use in that stack, in bytes.  This used to be a
+	   conditional around just the two extra args, but that might
+	   be undefined if yyoverflow is a macro.  */
+	yyoverflow ("parser stack overflow",
+		    &yyss1, yysize * sizeof (*yyssp),
+		    &yyvs1, yysize * sizeof (*yyvsp),
+
+		    &yystacksize);
+
+	yyss = yyss1;
+	yyvs = yyvs1;
+      }
+#else /* no yyoverflow */
+# ifndef YYSTACK_RELOCATE
+      goto yyoverflowlab;
+# else
+      /* Extend the stack our own way.  */
+      if (YYMAXDEPTH <= yystacksize)
+	goto yyoverflowlab;
+      yystacksize *= 2;
+      if (YYMAXDEPTH < yystacksize)
+	yystacksize = YYMAXDEPTH;
+
+      {
+	short int *yyss1 = yyss;
+	union yyalloc *yyptr =
+	  (union yyalloc *) YYSTACK_ALLOC (YYSTACK_BYTES (yystacksize));
+	if (! yyptr)
+	  goto yyoverflowlab;
+	YYSTACK_RELOCATE (yyss);
+	YYSTACK_RELOCATE (yyvs);
+
+#  undef YYSTACK_RELOCATE
+	if (yyss1 != yyssa)
+	  YYSTACK_FREE (yyss1);
+      }
+# endif
+#endif /* no yyoverflow */
+
+      yyssp = yyss + yysize - 1;
+      yyvsp = yyvs + yysize - 1;
+
+
+      YYDPRINTF ((stderr, "Stack size increased to %lu\n",
+		  (unsigned long int) yystacksize));
+
+      if (yyss + yystacksize - 1 <= yyssp)
+	YYABORT;
+    }
+
+  YYDPRINTF ((stderr, "Entering state %d\n", yystate));
+
+  goto yybackup;
+
+/*-----------.
+| yybackup.  |
+`-----------*/
+yybackup:
+
+/* Do appropriate processing given the current state.  */
+/* Read a lookahead token if we need one and don't already have one.  */
+/* yyresume: */
+
+  /* First try to decide what to do without reference to lookahead token.  */
+
+  yyn = yypact[yystate];
+  if (yyn == YYPACT_NINF)
+    goto yydefault;
+
+  /* Not known => get a lookahead token if don't already have one.  */
+
+  /* YYCHAR is either YYEMPTY or YYEOF or a valid lookahead symbol.  */
+  if (yychar == YYEMPTY)
+    {
+      YYDPRINTF ((stderr, "Reading a token: "));
+      yychar = YYLEX;
+    }
+
+  if (yychar <= YYEOF)
+    {
+      yychar = yytoken = YYEOF;
+      YYDPRINTF ((stderr, "Now at end of input.\n"));
+    }
+  else
+    {
+      yytoken = YYTRANSLATE (yychar);
+      YYDSYMPRINTF ("Next token is", yytoken, &yylval, &yylloc);
+    }
+
+  /* If the proper action on seeing token YYTOKEN is to reduce or to
+     detect an error, take that action.  */
+  yyn += yytoken;
+  if (yyn < 0 || YYLAST < yyn || yycheck[yyn] != yytoken)
+    goto yydefault;
+  yyn = yytable[yyn];
+  if (yyn <= 0)
+    {
+      if (yyn == 0 || yyn == YYTABLE_NINF)
+	goto yyerrlab;
+      yyn = -yyn;
+      goto yyreduce;
+    }
+
+  if (yyn == YYFINAL)
+    YYACCEPT;
+
+  /* Shift the lookahead token.  */
+  YYDPRINTF ((stderr, "Shifting token %s, ", yytname[yytoken]));
+
+  /* Discard the token being shifted unless it is eof.  */
+  if (yychar != YYEOF)
+    yychar = YYEMPTY;
+
+  *++yyvsp = yylval;
+
+
+  /* Count tokens shifted since error; after three, turn off error
+     status.  */
+  if (yyerrstatus)
+    yyerrstatus--;
+
+  yystate = yyn;
+  goto yynewstate;
+
+
+/*-----------------------------------------------------------.
+| yydefault -- do the default action for the current state.  |
+`-----------------------------------------------------------*/
+yydefault:
+  yyn = yydefact[yystate];
+  if (yyn == 0)
+    goto yyerrlab;
+  goto yyreduce;
+
+
+/*-----------------------------.
+| yyreduce -- Do a reduction.  |
+`-----------------------------*/
+yyreduce:
+  /* yyn is the number of a rule to reduce with.  */
+  yylen = yyr2[yyn];
+
+  /* If YYLEN is nonzero, implement the default value of the action:
+     `$$ = $1'.
+
+     Otherwise, the following line sets YYVAL to garbage.
+     This behavior is undocumented and Bison
+     users should not rely upon it.  Assigning to YYVAL
+     unconditionally makes the parser a bit smaller, and it avoids a
+     GCC warning that YYVAL may be used uninitialized.  */
+  yyval = yyvsp[1-yylen];
+
+
+  YY_REDUCE_PRINT (yyn);
+  switch (yyn)
+    {
+        case 2:
+#line 76 "arith.y"
+    {
+			return (yyvsp[0]);
+		;}
+    break;
+
+  case 3:
+#line 82 "arith.y"
+    { yyval = yyvsp[-1]; ;}
+    break;
+
+  case 4:
+#line 83 "arith.y"
+    { yyval = yyvsp[-2] ? yyvsp[-2] : yyvsp[0] ? yyvsp[0] : 0; ;}
+    break;
+
+  case 5:
+#line 84 "arith.y"
+    { yyval = yyvsp[-2] ? ( yyvsp[0] ? yyvsp[0] : 0 ) : 0; ;}
+    break;
+
+  case 6:
+#line 85 "arith.y"
+    { yyval = yyvsp[-2] | yyvsp[0]; ;}
+    break;
+
+  case 7:
+#line 86 "arith.y"
+    { yyval = yyvsp[-2] ^ yyvsp[0]; ;}
+    break;
+
+  case 8:
+#line 87 "arith.y"
+    { yyval = yyvsp[-2] & yyvsp[0]; ;}
+    break;
+
+  case 9:
+#line 88 "arith.y"
+    { yyval = yyvsp[-2] == yyvsp[0]; ;}
+    break;
+
+  case 10:
+#line 89 "arith.y"
+    { yyval = yyvsp[-2] > yyvsp[0]; ;}
+    break;
+
+  case 11:
+#line 90 "arith.y"
+    { yyval = yyvsp[-2] >= yyvsp[0]; ;}
+    break;
+
+  case 12:
+#line 91 "arith.y"
+    { yyval = yyvsp[-2] < yyvsp[0]; ;}
+    break;
+
+  case 13:
+#line 92 "arith.y"
+    { yyval = yyvsp[-2] <= yyvsp[0]; ;}
+    break;
+
+  case 14:
+#line 93 "arith.y"
+    { yyval = yyvsp[-2] != yyvsp[0]; ;}
+    break;
+
+  case 15:
+#line 94 "arith.y"
+    { yyval = yyvsp[-2] << yyvsp[0]; ;}
+    break;
+
+  case 16:
+#line 95 "arith.y"
+    { yyval = yyvsp[-2] >> yyvsp[0]; ;}
+    break;
+
+  case 17:
+#line 96 "arith.y"
+    { yyval = yyvsp[-2] + yyvsp[0]; ;}
+    break;
+
+  case 18:
+#line 97 "arith.y"
+    { yyval = yyvsp[-2] - yyvsp[0]; ;}
+    break;
+
+  case 19:
+#line 98 "arith.y"
+    { yyval = yyvsp[-2] * yyvsp[0]; ;}
+    break;
+
+  case 20:
+#line 99 "arith.y"
+    {
+			if (yyvsp[0] == 0)
+				yyerror("division by zero");
+			yyval = yyvsp[-2] / yyvsp[0];
+			;}
+    break;
+
+  case 21:
+#line 104 "arith.y"
+    {
+			if (yyvsp[0] == 0)
+				yyerror("division by zero");
+			yyval = yyvsp[-2] % yyvsp[0];
+			;}
+    break;
+
+  case 22:
+#line 109 "arith.y"
+    { yyval = !(yyvsp[0]); ;}
+    break;
+
+  case 23:
+#line 110 "arith.y"
+    { yyval = ~(yyvsp[0]); ;}
+    break;
+
+  case 24:
+#line 111 "arith.y"
+    { yyval = -(yyvsp[0]); ;}
+    break;
+
+  case 25:
+#line 112 "arith.y"
+    { yyval = yyvsp[0]; ;}
+    break;
+
+
+    }
+
+/* Line 1010 of yacc.c.  */
+#line 1276 "arith.c"
+
+  yyvsp -= yylen;
+  yyssp -= yylen;
+
+
+  YY_STACK_PRINT (yyss, yyssp);
+
+  *++yyvsp = yyval;
+
+
+  /* Now `shift' the result of the reduction.  Determine what state
+     that goes to, based on the state we popped back to and the rule
+     number reduced by.  */
+
+  yyn = yyr1[yyn];
+
+  yystate = yypgoto[yyn - YYNTOKENS] + *yyssp;
+  if (0 <= yystate && yystate <= YYLAST && yycheck[yystate] == *yyssp)
+    yystate = yytable[yystate];
+  else
+    yystate = yydefgoto[yyn - YYNTOKENS];
+
+  goto yynewstate;
+
+
+/*------------------------------------.
+| yyerrlab -- here on detecting error |
+`------------------------------------*/
+yyerrlab:
+  /* If not already recovering from an error, report this error.  */
+  if (!yyerrstatus)
+    {
+      ++yynerrs;
+#if YYERROR_VERBOSE
+      yyn = yypact[yystate];
+
+      if (YYPACT_NINF < yyn && yyn < YYLAST)
+	{
+	  YYSIZE_T yysize = 0;
+	  int yytype = YYTRANSLATE (yychar);
+	  const char* yyprefix;
+	  char *yymsg;
+	  int yyx;
+
+	  /* Start YYX at -YYN if negative to avoid negative indexes in
+	     YYCHECK.  */
+	  int yyxbegin = yyn < 0 ? -yyn : 0;
+
+	  /* Stay within bounds of both yycheck and yytname.  */
+	  int yychecklim = YYLAST - yyn;
+	  int yyxend = yychecklim < YYNTOKENS ? yychecklim : YYNTOKENS;
+	  int yycount = 0;
+
+	  yyprefix = ", expecting ";
+	  for (yyx = yyxbegin; yyx < yyxend; ++yyx)
+	    if (yycheck[yyx + yyn] == yyx && yyx != YYTERROR)
+	      {
+		yysize += yystrlen (yyprefix) + yystrlen (yytname [yyx]);
+		yycount += 1;
+		if (yycount == 5)
+		  {
+		    yysize = 0;
+		    break;
+		  }
+	      }
+	  yysize += (sizeof ("syntax error, unexpected ")
+		     + yystrlen (yytname[yytype]));
+	  yymsg = (char *) YYSTACK_ALLOC (yysize);
+	  if (yymsg != 0)
+	    {
+	      char *yyp = yystpcpy (yymsg, "syntax error, unexpected ");
+	      yyp = yystpcpy (yyp, yytname[yytype]);
+
+	      if (yycount < 5)
+		{
+		  yyprefix = ", expecting ";
+		  for (yyx = yyxbegin; yyx < yyxend; ++yyx)
+		    if (yycheck[yyx + yyn] == yyx && yyx != YYTERROR)
+		      {
+			yyp = yystpcpy (yyp, yyprefix);
+			yyp = yystpcpy (yyp, yytname[yyx]);
+			yyprefix = " or ";
+		      }
+		}
+	      yyerror (yymsg);
+	      YYSTACK_FREE (yymsg);
+	    }
+	  else
+	    yyerror ("syntax error; also virtual memory exhausted");
+	}
+      else
+#endif /* YYERROR_VERBOSE */
+	yyerror ("syntax error");
+    }
+
+
+
+  if (yyerrstatus == 3)
+    {
+      /* If just tried and failed to reuse lookahead token after an
+	 error, discard it.  */
+
+      if (yychar <= YYEOF)
+        {
+          /* If at end of input, pop the error token,
+	     then the rest of the stack, then return failure.  */
+	  if (yychar == YYEOF)
+	     for (;;)
+	       {
+		 YYPOPSTACK;
+		 if (yyssp == yyss)
+		   YYABORT;
+		 YYDSYMPRINTF ("Error: popping", yystos[*yyssp], yyvsp, yylsp);
+		 yydestruct (yystos[*yyssp], yyvsp);
+	       }
+        }
+      else
+	{
+	  YYDSYMPRINTF ("Error: discarding", yytoken, &yylval, &yylloc);
+	  yydestruct (yytoken, &yylval);
+	  yychar = YYEMPTY;
+
+	}
+    }
+
+  /* Else will try to reuse lookahead token after shifting the error
+     token.  */
+  goto yyerrlab1;
+
+
+/*---------------------------------------------------.
+| yyerrorlab -- error raised explicitly by YYERROR.  |
+`---------------------------------------------------*/
+yyerrorlab:
+
+#ifdef __GNUC__
+  /* Pacify GCC when the user code never invokes YYERROR and the label
+     yyerrorlab therefore never appears in user code.  */
+  if (0)
+     goto yyerrorlab;
+#endif
+
+  yyvsp -= yylen;
+  yyssp -= yylen;
+  yystate = *yyssp;
+  goto yyerrlab1;
+
+
+/*-------------------------------------------------------------.
+| yyerrlab1 -- common code for both syntax error and YYERROR.  |
+`-------------------------------------------------------------*/
+yyerrlab1:
+  yyerrstatus = 3;	/* Each real token shifted decrements this.  */
+
+  for (;;)
+    {
+      yyn = yypact[yystate];
+      if (yyn != YYPACT_NINF)
+	{
+	  yyn += YYTERROR;
+	  if (0 <= yyn && yyn <= YYLAST && yycheck[yyn] == YYTERROR)
+	    {
+	      yyn = yytable[yyn];
+	      if (0 < yyn)
+		break;
+	    }
+	}
+
+      /* Pop the current state because it cannot handle the error token.  */
+      if (yyssp == yyss)
+	YYABORT;
+
+      YYDSYMPRINTF ("Error: popping", yystos[*yyssp], yyvsp, yylsp);
+      yydestruct (yystos[yystate], yyvsp);
+      YYPOPSTACK;
+      yystate = *yyssp;
+      YY_STACK_PRINT (yyss, yyssp);
+    }
+
+  if (yyn == YYFINAL)
+    YYACCEPT;
+
+  YYDPRINTF ((stderr, "Shifting error token, "));
+
+  *++yyvsp = yylval;
+
+
+  yystate = yyn;
+  goto yynewstate;
+
+
+/*-------------------------------------.
+| yyacceptlab -- YYACCEPT comes here.  |
+`-------------------------------------*/
+yyacceptlab:
+  yyresult = 0;
+  goto yyreturn;
+
+/*-----------------------------------.
+| yyabortlab -- YYABORT comes here.  |
+`-----------------------------------*/
+yyabortlab:
+  yyresult = 1;
+  goto yyreturn;
+
+#ifndef yyoverflow
+/*----------------------------------------------.
+| yyoverflowlab -- parser overflow comes here.  |
+`----------------------------------------------*/
+yyoverflowlab:
+  yyerror ("parser stack overflow");
+  yyresult = 2;
+  /* Fall through.  */
+#endif
+
+yyreturn:
+#ifndef yyoverflow
+  if (yyss != yyssa)
+    YYSTACK_FREE (yyss);
+#endif
+  return yyresult;
+}
+
+
+#line 115 "arith.y"
+
+int
+arith(s)
+	const char *s;
+{
+	long result;
+
+	arith_buf = arith_startbuf = s;
+
+	INTOFF;
+	result = yyparse();
+	arith_lex_reset();	/* reprime lex */
+	INTON;
+
+	return (result);
+}
+
+
+/*
+ *  The exp(1) builtin.
+ */
+int
+expcmd(argc, argv)
+	int argc;
+	char **argv;
+{
+	const char *p;
+	char *concat;
+	char **ap;
+	long i;
+
+	if (argc > 1) {
+		p = argv[1];
+		if (argc > 2) {
+			/*
+			 * concatenate arguments
+			 */
+			STARTSTACKSTR(concat);
+			ap = argv + 2;
+			for (;;) {
+				while (*p)
+					STPUTC(*p++, concat);
+				if ((p = *ap++) == NULL)
+					break;
+				STPUTC(' ', concat);
+			}
+			STPUTC('\0', concat);
+			p = grabstackstr(concat);
+		}
+	} else
+		p = "";
+
+	i = arith(p);
+
+	out1fmt("%ld\n", i);
+	return (! i);
+}
+
+/*************************/
+#ifdef TEST_ARITH
+#include <stdio.h>
+main(argc, argv)
+	char *argv[];
+{
+	printf("%d\n", exp(argv[1]));
+}
+error(s)
+	char *s;
+{
+	fprintf(stderr, "exp: %s\n", s);
+	exit(1);
+}
+#endif
+
+void
+yyerror(s)
+	const char *s;
+{
+
+//	yyerrok;
+	yyclearin;
+	arith_lex_reset();	/* reprime lex */
+	error("arithmetic expression: %s: \"%s\"", s, arith_startbuf);
+	/* NOTREACHED */
+}
+
+