* src/ltlvisit/nenoform.hh, src/ltlvisit/nenoform.cc: New files.

* src/ltlvisit/Makefile.am (libltlvisit_a_SOURCES): Add them.
* src/ltltest/equals.cc (main) [NENOFORM]: Call negative_normal_form.
* src/ltltest/nenoform.test, src/ltltest/tunenoform.test: New files.
* src/ltltest/Makefile.am (check_PROGRAMS): Add nenoform and
tunenoform.
(nenoform_SOURCES, nenoform_CPPFLAGS, tunenoform_SOURCES,
tunenoform_CPPFLAGS): New variables.
(TESTS): Add nenoform.test and tunenoform.test.

src/ltltest/.cvsignore

@@ -10,3 +10,5 @@ defs
 equals
 lunabbrev
 tunabbrev
+nenoform
+tunenoform

src/ltltest/Makefile.am

@@ -4,7 +4,17 @@ LDADD = ../ltlparse/libltlparse.a \
         ../ltlast/libltlast.a 
 
 check_SCRIPTS = defs
-check_PROGRAMS = ltl2dot ltl2text equals lunabbrev tunabbrev
+
+# Keep this sorted alphabetically.
+check_PROGRAMS = \
+  equals \
+  ltl2dot \
+  ltl2text \
+  lunabbrev \
+  nenoform \
+  tunabbrev \
+  tunenoform
+
 ltl2dot_SOURCES = readltl.cc
 ltl2dot_CPPFLAGS = $(AM_CPPFLAGS) -DDOTTY
 ltl2text_SOURCES = readltl.cc
@@ -13,8 +23,21 @@ lunabbrev_SOURCES = equals.cc
 lunabbrev_CPPFLAGS = $(AM_CPPFLAGS) -DLUNABBREV
 tunabbrev_SOURCES = equals.cc
 tunabbrev_CPPFLAGS = $(AM_CPPFLAGS) -DTUNABBREV
+nenoform_SOURCES = equals.cc
+nenoform_CPPFLAGS = $(AM_CPPFLAGS) -DNENOFORM
+tunenoform_SOURCES = equals.cc
+tunenoform_CPPFLAGS = $(AM_CPPFLAGS) -DNENOFORM -DTUNABBREV
 
 EXTRA_DIST = $(TESTS)
-TESTS = parse.test parseerr.test equals.test lunabbrev.test tunabbrev.test
+
+# Ordered by strength of the test.  Test basic features first.
+TESTS = \
+  parse.test \
+  parseerr.test \
+  equals.test \
+  lunabbrev.test \
+  tunabbrev.test \
+  nenoform.test \
+  tunenoform.test
 
 CLEANFILES = stdout expect parse.dot

src/ltltest/equals.cc

@@ -4,6 +4,7 @@
 #include "ltlvisit/lunabbrev.hh"
 #include "ltlvisit/tunabbrev.hh"
 #include "ltlvisit/dump.hh"
+#include "ltlvisit/nenoform.hh"
 
 void
 syntax(char *prog)
@@ -34,10 +35,17 @@ main(int argc, char **argv)
 #ifdef LUNABBREV
   f1 = spot::ltl::unabbreviate_logic(f1);
   spot::ltl::dump(*f1, std::cout);
+  std::cout << std::endl;
 #endif
 #ifdef TUNABBREV
   f1 = spot::ltl::unabbreviate_ltl(f1);
   spot::ltl::dump(*f1, std::cout);
+  std::cout << std::endl;
+#endif
+#ifdef NENOFORM
+  f1 = spot::ltl::negative_normal_form(f1);
+  spot::ltl::dump(*f1, std::cout);
+  std::cout << std::endl;
 #endif
 
   if (equals(f1, f2))

src/ltltest/nenoform.test

@@ -0,0 +1,49 @@
+#! /bin/sh
+
+# Check for the negative_normal_form visitor
+
+. ./defs || exit 1
+
+check()
+{
+  ./nenoform "$1" "$2" || exit 1
+}
+
+# A few things that do not change
+check 'a' 'a'
+check '1' '1'
+check '0' '0'
+check '!a' '!a'
+check 'a U b' 'a U b'
+check 'a & b' 'a & b'
+check 'a & b' 'b & a'
+check 'a & !b & c' 'c & a & !b'
+check 'a & b & c' 'b & c & a'
+check 'Xa & b & Xa' 'b & Xa & b'
+check 'a & b' 'b & a & b'
+check 'a & !b' '!b & a & a'
+check 'a & b & (Xc |(f U !g)| e)' 'b & a & a & (Xc | e |(f U !g)| e | Xc) & b'
+check 'GFa => FGb' 'GFa => FGb'
+
+# Basic rewritings
+check '!!a' 'a'
+check '!!!!!a' '!a'
+check '!Xa' 'X!a'
+check '!Fa' 'G!a'
+check '!Ga' 'F!a'
+check '!(a ^ b)' 'a <=> b'
+check '!(a <=> b)' '(((a) ^ (b)))'
+check '!(a => b)' 'a&!b'
+check '!(!a => !b)' '!a&b'
+check '!(a U b)' '!a R !b'
+check '!(a R b)' '!a U !b'
+check '!(!a R !b)' 'a U b'
+check '!(a & b & c & d & b)' '!a | !b | !c | !d'
+check '!(a | b | c | d)' '!a & !b & !c & !d'
+
+# Nested rewritings
+check '!(a U (!b U ((a & b & c) R d)))' '!a R (b R ((!a | !b | !c) U !d))'
+check '!(GF a => FG b)' 'GFa & GF!b'
+
+# Success.
+:

src/ltltest/tunenoform.test

@@ -0,0 +1,21 @@
+#! /bin/sh
+
+# Check for unabbreviate_ltl + negative_normal_form visitors
+
+. ./defs || exit 1
+
+check()
+{
+  ./tunenoform "$1" "$2" || exit 1
+}
+
+check '!(a ^ b)' '(a|!b) & (!a|b)'
+check '!(a <=> b)' '(a|b) & (!a|!b)'
+check '!(a => b)' 'a&!b'
+check '!(!a => !b)' '!a&b'
+check '!Fa' 'false R !a'
+check '!G!a' 'true U a'
+check '!(GF a => FG b)' '(0 R (1 U a)) & (0 R (1 U !b))'
+
+# Success.
+: