diff --git a/NEWS b/NEWS index 928a25da2..5e7816b7b 100644 --- a/NEWS +++ b/NEWS @@ -9,8 +9,17 @@ New in spot 2.10.4.dev (net yet released) - autfilt has a new --to-finite option, illustrated on https://spot.lrde.epita.fr/tut12.html + - ltlfilt has a new --sonf option to produce a formula's Suffix + Operator Normal Form, described in [cimatti.06.fmcad]. The + associated option --sonf-aps allows listing the newly introduced + atomic propositions. + Library: + - The new function suffix_operator_normal_form() implements + transformation of formulas to Suffix Operator Normal Form, + described in [cimatti.06.fmcad]. + - "original-classes" is a new named property similar to "original-states". It maps an each state to an unsigned integer such that if two classes are in the same class, they are expected diff --git a/bin/ltlfilt.cc b/bin/ltlfilt.cc index cc9e0f02b..af9316192 100644 --- a/bin/ltlfilt.cc +++ b/bin/ltlfilt.cc @@ -38,6 +38,7 @@ #include #include #include +#include #include #include #include @@ -100,6 +101,8 @@ enum { OPT_SIZE_MAX, OPT_SIZE_MIN, OPT_SKIP_ERRORS, + OPT_SONF, + OPT_SONF_APS, OPT_STUTTER_INSENSITIVE, OPT_SUSPENDABLE, OPT_SYNTACTIC_GUARANTEE, @@ -127,6 +130,11 @@ static const argp_option options[] = { "negate", OPT_NEGATE, nullptr, 0, "negate each formula", 0 }, { "nnf", OPT_NNF, nullptr, 0, "rewrite formulas in negative normal form", 0 }, + { "sonf", OPT_SONF, "PREFIX", OPTION_ARG_OPTIONAL, + "rewrite formulas in suffix operator normal form", 0 }, + { "sonf-aps", OPT_SONF_APS, "FILENAME", OPTION_ARG_OPTIONAL, + "when used with --sonf, output the newly introduced atomic " + "propositions", 0 }, { "relabel", OPT_RELABEL, "abc|pnn", OPTION_ARG_OPTIONAL, "relabel all atomic propositions, alphabetically unless " \ "specified otherwise", 0 }, @@ -316,6 +324,7 @@ static range opt_nth = { 0, std::numeric_limits::max() }; static int opt_max_count = -1; static long int match_count = 0; static const char* from_ltlf = nullptr; +static const char* sonf = nullptr; // We want all these variables to be destroyed when we exit main, to @@ -327,6 +336,7 @@ static struct opt_t spot::bdd_dict_ptr dict = spot::make_bdd_dict(); spot::exclusive_ap excl_ap; std::unique_ptr output_define = nullptr; + std::unique_ptr output_sonf = nullptr; spot::formula implied_by = nullptr; spot::formula imply = nullptr; spot::formula equivalent_to = nullptr; @@ -460,6 +470,12 @@ parse_opt(int key, char* arg, struct argp_state*) case OPT_NNF: nnf = true; break; + case OPT_SONF: + sonf = arg ? arg : "sonf_"; + break; + case OPT_SONF_APS: + opt->output_sonf.reset(new output_file(arg ? arg : "-")); + break; case OPT_OBLIGATION: obligation = true; break; @@ -650,6 +666,25 @@ namespace if (nnf) f = simpl.negative_normal_form(f); + if (sonf != nullptr) + { + std::vector new_aps; + std::tie(f, new_aps) = suffix_operator_normal_form(f, sonf); + + if (opt->output_sonf + && output_format != count_output + && output_format != quiet_output) + { + for (size_t i = 0; i < new_aps.size(); ++i) + { + if (i > 0) + opt->output_sonf->ostream() << ' '; + opt->output_sonf->ostream() << new_aps[i]; + } + opt->output_sonf->ostream() << '\n'; + } + } + switch (relabeling) { case ApRelabeling: diff --git a/doc/spot.bib b/doc/spot.bib index 9f18ad2a9..9d5d6b235 100644 --- a/doc/spot.bib +++ b/doc/spot.bib @@ -214,6 +214,18 @@ doi = {10.1109/DepCoS-RELCOMEX.2009.31} } +@InProceedings{ cimatti.06.fmcad, + author = {Cimatti, Alessandro and Roveri, Marco and Semprini, Simone and + Tonetta, Stefano}, + title = {From {PSL} to {NBA}: a Modular Symbolic Encoding}, + booktitle = {Proceedings of the 6th conference on Formal Methods in Computer + Aided Design (FMCAD'06)}, + pages = {125--133}, + year = {2006}, + publisher = {IEEE Computer Society}, + doi = {10.1109/FMCAD.2006.19} +} + @Article{ cimatti.08.tcad, author = {Alessandro Cimatti and Marco Roveri and Stefano Tonetta}, journal = {IEEE Transactions on Computer Aided Design of Integrated diff --git a/python/spot/impl.i b/python/spot/impl.i index 90a38a55a..7132a5cc6 100644 --- a/python/spot/impl.i +++ b/python/spot/impl.i @@ -94,6 +94,7 @@ #include #include #include +#include #include #include #include @@ -517,6 +518,7 @@ namespace std { %template(vectorbdd) vector; %template(aliasvector) vector>; %template(vectorstring) vector; + %template(pair_formula_vectorstring) pair>; %template(atomic_prop_set) set; %template(relabeling_map) map; } @@ -577,6 +579,7 @@ namespace std { %include %include %include +%include %include %include %include diff --git a/spot/tl/Makefile.am b/spot/tl/Makefile.am index b7362ae99..cdedddffd 100644 --- a/spot/tl/Makefile.am +++ b/spot/tl/Makefile.am @@ -44,6 +44,7 @@ tl_HEADERS = \ remove_x.hh \ simplify.hh \ snf.hh \ + sonf.hh \ unabbrev.hh noinst_LTLIBRARIES = libtl.la @@ -68,4 +69,5 @@ libtl_la_SOURCES = \ remove_x.cc \ simplify.cc \ snf.cc \ + sonf.cc \ unabbrev.cc diff --git a/spot/tl/sonf.cc b/spot/tl/sonf.cc new file mode 100644 index 000000000..29a319039 --- /dev/null +++ b/spot/tl/sonf.cc @@ -0,0 +1,185 @@ +// -*- coding: utf-8 -*- +// Copyright (C) 2021 Laboratoire de Recherche et Developpement de +// l'Epita (LRDE). +// +// This file is part of Spot, a model checking library. +// +// Spot 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 3 of the License, or +// (at your option) any later version. +// +// Spot 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, see . + +#include "config.h" +#include +#include + +#include +#include +#include +#include + +namespace spot +{ + namespace + { + /// Uses `extractor` to extract some parts of the formula and replace them + /// with atomic propositions. + /// + /// Returns (f & g1 & g2 & .. & gn) with g1..gn the extracted subformulas. + /// + /// `extractor` should be a lambda taking the following parameters as input: + /// + /// - `formula` the formula to process + /// - `std::vector&` the vector that stores extracted subformulas + /// - `auto&&` itself, in case it needs to call itself recursively + /// (formula::map for example) + /// - `bool` a boolean indicating whether the lambda is currently being + /// called at the formula's "root" + /// - `bool` a boolean indicating whether the lambda is currently being + /// called inside a toplevel `and` construct. + /// + /// Note that the last 2 boolean arguments can be used as you see fit in + /// your recursive calls, the first one being set to true in the original + /// call, and the second one to false. + /// + /// `extractor` should return the new rewritten formula. + /// + /// auto sample_extractor = [](formula f, + /// std::vector& extracted, + /// auto&& extractor, + /// bool top_level, + /// bool in_top_level_and) -> formula + template + static formula + extract(formula f, Ext extractor) + { + std::vector extracted; + formula new_f = extractor(f, extracted, extractor, true, false); + extracted.push_back(new_f); + return formula::And(extracted); + } + } + + std::pair> + suffix_operator_normal_form(formula f, const std::string prefix) + { + // SONF can only be applied to formulas in negative normal form + f = negative_normal_form(f); + + std::unordered_set used_aps; + std::vector added_aps; + size_t count = 0; + + // identify all used ap names to avoid them when generating new ones + auto ap_indexer = [&used_aps](formula f) noexcept { + if (f.is(op::ap)) + { + used_aps.insert(f.ap_name()); + return true; + } + + return false; + }; + + f.traverse(ap_indexer); + + auto new_ap_name = + [&used_aps, &added_aps, &prefix, &count]() noexcept -> std::string + { + std::string new_name = prefix + std::to_string(count++); + while (used_aps.find(new_name) != used_aps.end()) + new_name = prefix + std::to_string(count++); + used_aps.insert(new_name); + added_aps.push_back(new_name); + return new_name; + }; + + // extracts the SERE part and replaces it with an atomic proposition, + // storing the extracted formula in `extracted` and returning the rewritten + // original formula + auto sonf_extract = [&](formula f, + std::vector& extracted, + auto&& extractor, + bool top_level, + bool in_top_level_and) noexcept -> formula + { + const auto kind = f.kind(); + + switch (kind) + { + case op::G: + { + // skip if shape is G(!ap | (regex []-> formula)) and at top level + if ((top_level || in_top_level_and) + && f[0].is(op::Or) // G(_ | _) + && f[0][0].is(op::Not) // G(!_ | _) + && f[0][0][0].is(op::ap) // G(!ap | _) + && f[0][1].is(op::EConcat, op::UConcat)) // G(!ap | (_ []-> _)) + return f; + else + return f.map(extractor, extracted, extractor, false, false); + } + case op::EConcat: + case op::UConcat: + { + // recurse into rhs first (_ []-> rhs) + formula rhs = + f[1].map(extractor, extracted, extractor, false, false); + f = formula::binop(kind, f[0], rhs); + + formula ap = formula::ap(new_ap_name()); + extracted.push_back(formula::G(formula::Or({formula::Not(ap), f}))); + return ap; + } + default: + // tracking if we're in a op::And at the formula root + in_top_level_and = top_level && f.is(op::And); + return f.map(extractor, extracted, extractor, + false, in_top_level_and); + } + }; + + f = extract(f, sonf_extract); + + auto ltl_extract = [&](formula f, + std::vector& extracted, + auto&& extractor, + [[maybe_unused]] + bool top_level, + [[maybe_unused]] + bool in_top_level_and) noexcept -> formula + { + switch (f.kind()) + { + case op::EConcat: + case op::UConcat: + { + formula rhs = f[1]; + + if (rhs.is(op::ap)) + return f; + + formula ap = formula::ap(new_ap_name()); + extracted.push_back( + formula::G(formula::Or({formula::Not(ap), rhs}))); + + return formula::binop(f.kind(), f[0], ap); + } + default: + return f.map(extractor, extracted, extractor, false, false); + } + }; + + f = extract(f, ltl_extract); + + return {f, added_aps}; + } +} diff --git a/spot/tl/sonf.hh b/spot/tl/sonf.hh new file mode 100644 index 000000000..37ef5d05d --- /dev/null +++ b/spot/tl/sonf.hh @@ -0,0 +1,44 @@ +// -*- coding: utf-8 -*- +// Copyright (C) 2021 Laboratoire de Recherche et Développement de +// l'Epita (LRDE). +// +// This file is part of Spot, a model checking library. +// +// Spot 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 3 of the License, or +// (at your option) any later version. +// +// Spot 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, see . + +#pragma once + +#include +#include +#include + +#include + +namespace spot +{ + /// \ingroup tl_rewriting + /// \brief Helper to rewrite a PSL formula in Suffix Operator Normal Form. + /// + /// SONF is described in section 4 of \cite cimatti.06.fmcad + /// + /// The formula output by this function is guaranteed to be in Negative Normal + /// Form. + /// + /// \param f the PSL formula to rewrite + /// \param prefix the prefix to use to name newly introduced aps + /// \return a pair with the rewritten formula, and a vector containing the + /// names of newly introduced aps + SPOT_API std::pair> + suffix_operator_normal_form(formula f, const std::string prefix); +} diff --git a/tests/Makefile.am b/tests/Makefile.am index 1b5d63fee..afcd0c8d2 100644 --- a/tests/Makefile.am +++ b/tests/Makefile.am @@ -198,7 +198,8 @@ TESTS_tl = \ core/stutter-ltl.test \ core/hierarchy.test \ core/mempool.test \ - core/format.test + core/format.test \ + core/sonf.test TESTS_graph = \ core/graph.test \ @@ -445,6 +446,7 @@ TESTS_python = \ python/setxor.py \ python/simplacc.py \ python/simstate.py \ + python/sonf.py \ python/split.py \ python/streett_totgba.py \ python/streett_totgba2.py \ diff --git a/tests/core/sonf.test b/tests/core/sonf.test new file mode 100644 index 000000000..0febfc342 --- /dev/null +++ b/tests/core/sonf.test @@ -0,0 +1,85 @@ +#!/bin/sh +# -*- coding: utf-8 -*- +# Copyright (C) 2021 Laboratoire de Recherche et Développement de +# l'Epita (LRDE). +# +# This file is part of Spot, a model checking library. +# +# Spot 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 3 of the License, or +# (at your option) any later version. +# +# Spot 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, see . + +. ./defs +set -e + +cat >input < Fa) & G(b -> ({x[*]}[]-> c)) +{x[*]}[]-> F({y[*]}<>-> GFz) +<>(({{p12}[*0..3]}[]-> ((p9) || (!(p17)))) V ((true) U (p17))) +{{true} || {[*0]}}[]-> (false) +{{p14} & {{p0}[*]}}[]-> (p11) +{{{!{p6}} -> {!{p3}}}[*]}[]-> ((p3)V((p3) || ((X((false))) && ((p2)V(p18))))) +X({{true} || {[*0]}}[]-> ((p17) U ((p8) && (p17)))) +({{{p4} || {p5} || {{p16} <-> {{p15} -> {p11}}}}[*]}[]-> (false)) -> (p8) +{[*1..6]}[]-> ((p9) V ((p9) || (!((p4) && (p19))))) +X({{{[*0]} || {{{p10};{p14}}[:*2..3]}}[:*]}<>-> (p8)) +{{true} && {{p8}[*]}}<>-> (!(p10)) +<>(!(({{p7}[*1..2]}<>-> (p11)) V ((!(p9)) && ([]((p11) || (X(p10))))))) +<>({{!{{p5} || {{!{p2}} <-> {p7}}}} & {[*]}}<>-> (p17)) +{{p0} || {{{[*0..2]}[:*2]}[*]}}<>-> ((p1) && (p6)) +EOF + +cat >expected < c)) +s1&G(!s2|GFz)&G(!s0|({y[*]}<>-> s2))&G(!s3|Fs0)&G(!s1|({x[*]}[]-> s3)) +F(s0 R (1 U p17))&G(p9|!p17|!s1)&G(!s0|({p12[*0..3]}[]-> s1)) +s0&G!s1&G(!s0|({1|[*0]}[]-> s1)) +s0&G(!s0|({p14&p0[*]}[]-> p11)) +s0&G(!s1|(p3 R (p3|(X(0)&(p2 R p18)))))&G(!s0|({{!p3|p6}[*]}[]-> s1)) +Xs0&G(!s1|(p17 U (p8&p17)))&G(!s0|({1|[*0]}[]-> s1)) +(p8|s0)&G(!s0|({{p4|p5|{p16 && {p11|!p15}}|{!p11 && p15 && !p16}}[*]}<>-> s1)) +s0&G(!s1|(p9 R (!p4|p9|!p19)))&G(!s0|({[*1..6]}[]-> s1)) +G(!s0|({{[*0]|{p10;p14}[:*2..3]}[:*]}<>-> p8))&Xs0 +s0&G(!p10|!s1)&G(!s0|({1 && p8[*]}<>-> s1)) +F(s0 U (p9|F(!p11&X!p10)))&G(!p11|!s1)&G(!s0|({p7[*1..2]}[]-> s1)) +G(!s0|({{!p5 && {{!p2 && !p7}|{p2 && p7}}}&[*]}<>-> p17))&Fs0 +s0&G(!s1|(p1&p6))&G(!s0|({p0|[*0..2][:*2][*]}<>-> s1)) +EOF + +cat >expected-aps < stdout +diff expected stdout +diff expected-aps stdout-aps + +# check idempotence +ltlfilt -F expected --sonf=s --sonf-aps=stdout-aps \ + | sed 's/ \([|&]\) /\1/g' > stdout +diff expected stdout +# should be 14 empty lines, no new aps introduced this time +test "$(wc -l -m stdout-aps | awk '{print $1 " " $2}')" = "14 14" diff --git a/tests/python/formulas.ipynb b/tests/python/formulas.ipynb index 95241be9d..7075cf653 100644 --- a/tests/python/formulas.ipynb +++ b/tests/python/formulas.ipynb @@ -976,6 +976,62 @@ "print(ap) # print as a string\n", "display(ap) # LaTeX-style, for notebooks" ] + }, + { + "cell_type": "markdown", + "metadata": {}, + "source": [ + "Converting to Suffix Operator Normal Form:" + ] + }, + { + "cell_type": "code", + "execution_count": 27, + "metadata": {}, + "outputs": [ + { + "data": { + "text/latex": [ + "$\\mathsf{G} (\\{x^{\\star}\\}\\mathrel{\\Box\\kern-1.7pt\\raise.4pt\\hbox{$\\mathord{\\rightarrow}$}} \\mathsf{F} a)$" + ], + "text/plain": [ + "spot.formula(\"G({x[*]}[]-> Fa)\")" + ] + }, + "metadata": {}, + "output_type": "display_data" + }, + { + "data": { + "text/latex": [ + "$\\mathsf{G} \\mathit{sonf\\_}_{0} \\land \\mathsf{G} (\\lnot \\mathit{sonf\\_}_{1} \\lor \\mathsf{F} a) \\land \\mathsf{G} (\\lnot \\mathit{sonf\\_}_{0} \\lor (\\{x^{\\star}\\}\\mathrel{\\Box\\kern-1.7pt\\raise.4pt\\hbox{$\\mathord{\\rightarrow}$}} \\mathit{sonf\\_}_{1}))$" + ], + "text/plain": [ + "spot.formula(\"Gsonf_0 & G(!sonf_1 | Fa) & G(!sonf_0 | ({x[*]}[]-> sonf_1))\")" + ] + }, + "metadata": {}, + "output_type": "display_data" + }, + { + "data": { + "text/plain": [ + "('sonf_0', 'sonf_1')" + ] + }, + "metadata": {}, + "output_type": "display_data" + } + ], + "source": [ + "f = spot.formula('G({x*} []-> Fa)')\n", + "display(f)\n", + "\n", + "# In addition to the formula, returns a list of newly introduced APs\n", + "f, aps = spot.suffix_operator_normal_form(f, 'sonf_')\n", + "display(f)\n", + "display(aps)" + ] } ], "metadata": { diff --git a/tests/python/sonf.py b/tests/python/sonf.py new file mode 100644 index 000000000..558f90c63 --- /dev/null +++ b/tests/python/sonf.py @@ -0,0 +1,41 @@ +# -*- mode: python; coding: utf-8 -*- +# Copyright (C) 2020 Laboratoire de Recherche et Développement de l'Epita +# (LRDE). +# +# This file is part of Spot, a model checking library. +# +# Spot 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 3 of the License, or +# (at your option) any later version. +# +# Spot 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, see . + +import spot + +formulas = """\ +{x[*]}[]-> F({y[*]}<>-> GFz) +<>(({{p12}[*0..3]}[]-> ((p9) || (!(p17)))) V ((true) U (p17))) +{{true} || {[*0]}}[]-> (false) +{{p14} & {{p0}[*]}}[]-> (p11) +{{{!{p6}} -> {!{p3}}}[*]}[]-> ((p3)V((p3) || ((X((false))) && ((p2)V(p18))))) +""" + +for f1 in formulas.splitlines(): + f1 = spot.formula(f1) + a1 = spot.translate(f1) + + f2, aps = spot.suffix_operator_normal_form(f1, 'sonf_') + a2 = spot.translate(f2) + rm = spot.remove_ap() + for ap in aps: + rm.add_ap(ap) + a2 = rm.strip(a2) + + assert(spot.are_equivalent(a1, a2))