Adding function to canonicalize an automaton.

* src/tgbaalgos/are_isomorphic.cc, src/tgbaalgos/are_isomorphic.hh,
src/bin/autfilt.cc: are_isomorphic now uses canonicalize. It returns a
bool, because the mapping cannot be deduced easily from the
canonicalized automaton.
* src/graph/graph.hh: Add equality operator to trans_storage_t
for easy comparison of transition vectors.
* src/tgba/tgbagraph.hh: Add equality operator to tgba_graph_trans_data
and to tgba_digraph.
* src/tgbaalgos/canonicalize.cc, src/tgbaalgos/canonicalize.hh:
New files.
* src/tgbaalgos/Makefile.am: Add them.
* src/tgbatest/isomorph.test: Test them.

src/tgbatest/isomorph.test

@@ -23,7 +23,7 @@
 set -e
 
 for i in 0 1 2 3 4; do
-  ../../bin/randaut a --seed=$i -S4 --hoa >iso$i
+  ../../bin/randaut a b --seed=$i -S10 --hoa >iso$i
   ../../bin/autfilt iso$i --randomize --hoa >aut$i
 done
 
@@ -32,3 +32,73 @@ cat aut0 aut1 aut2 aut3 aut4 > all
   run 0 ../../bin/autfilt all --are-isomorphic iso$i --hoa
 done) > output
 diff all output
+
+# Test if two isomorphic automata with different initial states are detected.
+cat >aut1 <<EOF
+HOA: v1
+name: "1"
+States: 4
+Start: 1
+AP: 0
+acc-name: all
+Acceptance: 0 t
+properties: trans-labels explicit-labels state-acc complete
+--BODY--
+State: 0 [t] 1 [t] 1
+State: 1 [t] 2 [t] 2
+State: 2 [t] 3 [t] 3
+State: 3 [t] 0 [t] 0
+--END--
+EOF
+
+cat >aut2 <<EOF
+HOA: v1
+name: "1"
+States: 4
+Start: 0
+AP: 0
+acc-name: all
+Acceptance: 0 t
+properties: trans-labels explicit-labels state-acc complete
+--BODY--
+State: 0 [t] 1 [t] 1
+State: 1 [t] 3 [t] 3
+State: 3 [t] 2 [t] 2
+State: 2 [t] 0 [t] 0
+--END--
+EOF
+
+# Check that the number of ingoing and outgoing transitions of a state matters,
+# even if they behave similarly.
+cat >aut3 <<EOF
+HOA: v1
+States: 3
+Start: 0
+AP: 0
+acc-name: all
+Acceptance: 0 t
+properties: trans-labels explicit-labels state-acc complete
+--BODY--
+State: 0 [t] 1 [t] 2
+State: 1 [t] 1 [t] 1
+State: 2 [t] 2
+--END--
+EOF
+
+cat >aut4 <<EOF
+HOA: v1
+States: 3
+Start: 0
+AP: 0
+acc-name: all
+Acceptance: 0 t
+properties: trans-labels explicit-labels state-acc complete
+--BODY--
+State: 0 [t] 1 [t] 2
+State: 1 [t] 1
+State: 2 [t] 2 [t] 2
+--END--
+EOF
+
+run 0 ../../bin/autfilt aut1 --are-isomorphic aut2
+run 0 ../../bin/autfilt aut3 --are-isomorphic aut4