ltl2tgba, ltldo: fix location of --negate in --help output

* bin/common_finput.cc, bin/ltl2tgba.cc, bin/ltldo.cc: Make sure
--negate is listed along with input options.

bin/common_finput.cc

@@ -37,16 +37,16 @@ static bool lenient = false;
 static const argp_option options[] =
   {
     { nullptr, 0, nullptr, 0, "Input options:", 1 },
-    { "formula", 'f', "STRING", 0, "process the formula STRING", 1 },
+    { "formula", 'f', "STRING", 0, "process the formula STRING", 0 },
     { "file", 'F', "FILENAME[/COL]", 0,
       "process each line of FILENAME as a formula; if COL is a "
       "positive integer, assume a CSV file and read column COL; use "
-      "a negative COL to drop the first line of the CSV file", 1 },
+      "a negative COL to drop the first line of the CSV file", 0 },
     { "lbt-input", OPT_LBT, nullptr, 0,
-      "read all formulas using LBT's prefix syntax", 1 },
+      "read all formulas using LBT's prefix syntax", 0 },
     { "lenient", OPT_LENIENT, nullptr, 0,
       "parenthesized blocks that cannot be parsed as subformulas "
-      "are considered as atomic properties", 1 },
+      "are considered as atomic properties", 0 },
     { nullptr, 0, nullptr, 0, nullptr, 0 }
   };
 

bin/ltl2tgba.cc

@@ -70,7 +70,7 @@ static const argp_option options[] =
 
 const struct argp_child children[] =
   {
-    { &finput_argp, 0, nullptr, 1 },
+    { &finput_argp, 0, nullptr, 0 },
     { &aoutput_argp, 0, nullptr, 0 },
     { &aoutput_o_format_argp, 0, nullptr, 0 },
     { &post_argp, 0, nullptr, 0 },

bin/ltldo.cc

@@ -153,7 +153,7 @@ ARGMATCH_VERIFY(errors_args, errors_types);
 const struct argp_child children[] =
   {
     { &hoaread_argp, 0, "Parsing of automata:", 3 },
-    { &finput_argp, 0, nullptr, 1 },
+    { &finput_argp, 0, nullptr, 0 },
     { &trans_argp, 0, nullptr, 3 },
     { &aoutput_argp, 0, nullptr, 6 },
     { build_percent_list(), 0, nullptr, 7 },