Simulation keeps track of simulated states in the input automaton.

* NEWS: Document the change.
* spot/twaalgos/simulation.cc: Implement the change.
* spot/twa/twagraph.cc: `copy_state_names_from` uses simulated states
  info if present.
* spot/twaalgos/determinize.cc: Pretty-print in determinization follows
  simulated states, avoiding possible confusion.
* tests/Makefile.am, tests/python/simstate.py: Add a test.

tests/Makefile.am

@@ -362,6 +362,7 @@ TESTS_python = \
   python/sccinfo.py \
   python/setacc.py \
   python/setxor.py \
+  python/simstate.py \
   python/rs_like.py \
   python/sum.py \
   python/trival.py \

tests/python/simstate.py

@@ -0,0 +1,169 @@
+# -*- mode: python; coding: utf-8 -*-
+# Copyright (C) 2015, 2017  Laboratoire de Recherche et Développement
+# de l'Epita
+#
+# 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 <http://www.gnu.org/licenses/>.
+
+import spot
+from sys import exit
+
+aut = spot.automaton("""
+HOA: v1
+States: 2
+Start: 0
+AP: 2 "a" "b"
+acc-name: Buchi
+Acceptance: 1 Inf(0)
+--BODY--
+State: 0
+[t] 1 {0}
+State: 1
+[t] 1 {0}
+--END--
+""")
+
+aut2 = spot.simulation(aut)
+assert aut2.to_str() == """HOA: v1
+States: 1
+Start: 0
+AP: 2 "a" "b"
+acc-name: Buchi
+Acceptance: 1 Inf(0)
+properties: trans-labels explicit-labels state-acc colored complete
+properties: deterministic
+--BODY--
+State: 0 {0}
+[t] 0
+--END--"""
+
+aut2.copy_state_names_from(aut)
+assert aut2.to_str() == """HOA: v1
+States: 1
+Start: 0
+AP: 2 "a" "b"
+acc-name: Buchi
+Acceptance: 1 Inf(0)
+properties: trans-labels explicit-labels state-acc colored complete
+properties: deterministic
+--BODY--
+State: 0 "[0,1]" {0}
+[t] 0
+--END--"""
+
+aut = spot.translate('GF((p0 -> Gp0) R p1)')
+
+daut = spot.tgba_determinize(aut, True)
+assert daut.to_str() == """HOA: v1
+States: 3
+Start: 0
+AP: 2 "p1" "p0"
+acc-name: parity min odd 4
+Acceptance: 4 Fin(0) & (Inf(1) | (Fin(2) & Inf(3)))
+properties: trans-labels explicit-labels trans-acc complete
+properties: deterministic stutter-invariant
+--BODY--
+State: 0 "{₀[1]₀}"
+[0&1] 1 {3}
+[!0&1] 0
+[0&!1] 0 {1}
+[!0&!1] 0
+State: 1 "{₀[1]{₂[0]₂}₀}{₁[2]₁}"
+[0&1] 1 {3}
+[!0&1] 2
+[0&!1] 0 {1}
+[!0&!1] 0 {2}
+State: 2 "{₀[1]₀}{₁[2]₁}"
+[0&1] 1 {3}
+[!0&1] 2
+[0&!1] 0 {1}
+[!0&!1] 0 {2}
+--END--"""
+
+aut = spot.automaton("""
+HOA: v1
+States: 2
+Start: 0
+AP: 2 "a" "b"
+Acceptance: 2 Inf(0)&Inf(1)
+--BODY--
+State: 0
+[0] 0
+[1] 1 {1}
+State: 1
+[0] 1 {0}
+[1] 0
+--END--
+""")
+
+daut = spot.tgba_determinize(aut, True)
+assert daut.to_str() == """HOA: v1
+States: 12
+Start: 0
+AP: 2 "a" "b"
+acc-name: parity min odd 4
+Acceptance: 4 Fin(0) & (Inf(1) | (Fin(2) & Inf(3)))
+properties: trans-labels explicit-labels trans-acc deterministic
+--BODY--
+State: 0 "{₀[0,0]₀}"
+[0&!1] 0
+[0&1] 1
+[!0&1] 2
+State: 1 "{₀[0,0] [1]₀}"
+[0&!1] 3
+[0&1] 4
+[!0&1] 1
+State: 2 "{₀[1]₀}"
+[0&!1] 5 {1}
+[0&1] 3
+[!0&1] 0
+State: 3 "{₀[0,0]{₁[1]₁}₀}"
+[0&!1] 3
+[0&1] 6
+[!0&1] 7
+State: 4 "{₀[0,0] [1]{₁[1]₁}₀}"
+[0&!1] 3
+[0&1] 6
+[!0&1] 7
+State: 5 "{₀[1]₀}"
+[0&!1] 5
+[0&1] 8
+[!0&1] 0
+State: 6 "{₀[1]{₁[0,0] [1]₁}₀}"
+[0&!1] 8 {1}
+[0&1] 9 {1}
+[!0&1] 1 {1}
+State: 7 "{₀[1]{₁[0,0]₁}₀}"
+[0&!1] 8 {1}
+[0&1] 9 {1}
+[!0&1] 10
+State: 8 "{₀[0,0] [1]₀}"
+[0&!1] 8
+[0&1] 9
+[!0&1] 1
+State: 9 "{₀[0,0] [1] [1]₀}"
+[0&!1] 3
+[0&1] 4
+[!0&1] 1
+State: 10 "{₀[0,0]{₁[1]₁}₀}"
+[0&!1] 3 {3}
+[0&1] 11
+[!0&1] 7
+State: 11 "{₀[1]{₁[0,0]{₂[1]₂}₁}₀}"
+[0&!1] 8 {1}
+[0&1] 9 {1}
+[!0&1] 1 {1}
+--END--"""
+