more doc handling of prop_universal for fused initial states

Fixes #560.

* spot/parseaut/parseaut.yy: Add more comments about handling
of prop_universal in present of multiple initial states.  It took
me time to figure out that it was done correctly.  Also only
reset prop_complete() in the case an initial state is reused.
* tests/core/det.test: Add a test case for the deterministic property.
* tests/python/parsetgba.py: Add tests for complete.
* doc/org/hoa.org: Add more text about the effect of fusing initial
states.
* doc/org/concepts.org (properties): Replace "deterministic" by
"universal".  The former was obsoleted in Spot 2.4.

tests/core/det.test

@@ -293,3 +293,31 @@ State: 1
 EOF
 autfilt -q --is-deterministic in.hoa && exit 1
 autfilt --merge-transitions in.hoa | autfilt --is-deterministic
+
+
+
+# This is a peculiarity of Spot: because it supports only one initial
+# state, but the HOA format allows for more, Spot's automaton parser
+# will fuse multiple initial states to fit into the Spot definition of
+# an automaton.  While this is preserving the original language, this
+# fusing of initial states may turn a non-deterministic automaton
+# (because of the multiple declared initial states) into a
+# deterministic one.  (Issue #560.)
+cat >560.hoa <<EOF
+HOA: v1.1
+States: 3
+Start: 1
+Start: 2
+AP: 1 "a"
+Acceptance: 0 t
+properties: !deterministic
+--BODY--
+State: 0
+[t] 0
+State: 1
+[0] 0
+State: 2
+[!0] 0
+--END--
+EOF
+test "1 2 1" = "`autfilt --stats='%d %[r]s %[u]s' 560.hoa`"

tests/python/parsetgba.py

@@ -191,3 +191,34 @@ State: 3
 [!0&2] 0
 [!0&!2] 3
 --END--""")
+
+
+# Spot supports only one initial state, but the HOA format allows for
+# more.  Spot's automaton parser will fuse multiple initial states to
+# fit into the Spot definition of an automaton.  Depending on how the
+# fusing is done, this can turn a complete automaton into a incomplete
+# one, and vice-versa.  See Issue #560.
+a = spot.automaton("""HOA: v1 States: 8 Start: 0 Start: 1 AP: 0
+acc-name: generalized-Buchi 2 properties: complete Acceptance: 2
+Inf(0)&Inf(1) --BODY-- State: 0 {0} [t] 2 [t] 3 [t] 0 State: 1 {0} [t]
+4 [t] 5 State: 2 {0} [t] 2 [t] 3 State: 3 {0} [t] 6 [t] 7 State: 4 {1}
+[t] 4 [t] 5 State: 5 {1} [t] 6 [t] 7 State: 6 [t] 6 [t] 7 State: 7 [t]
+6 [t] 7 --END--""")
+tc.assertTrue(a.prop_complete().is_true())
+
+a = spot.automaton("""HOA: v1 States: 8 Start: 0 Start: 1 AP: 0
+acc-name: generalized-Buchi 2 properties: complete Acceptance: 2
+Inf(0)&Inf(1) --BODY-- State: 0 {0} [t] 2 [t] 3 State: 1 {0} [t] 4 [t]
+5 State: 2 {0} [t] 2 [t] 3 State: 3 {0} [t] 6 [t] 7 State: 4 {1} [t] 4
+[t] 5 State: 5 {1} [t] 6 [t] 7 State: 6 [t] 6 [t] 7 State: 7 [t] 6 [t]
+7 --END--""")
+tc.assertTrue(a.prop_complete().is_false())
+
+a = spot.automaton("""HOA: v1.1 States: 8 Start: 0 Start: 1 AP: 1 "a"
+acc-name: generalized-Buchi 2 properties: !complete Acceptance: 2
+Inf(0)&Inf(1) --BODY-- State: 0 {0} [0] 2 [0] 3 State: 1 {0} [t] 1 [t]
+5 State: 2 {0} [t] 2 [t] 3 State: 3 {0} [t] 6 [t] 7 State: 4 {1} [t] 4
+[t] 5 State: 5 {1} [t] 6 [t] 7 State: 6 [t] 6 [t] 7 State: 7 [t] 6 [t]
+7 --END--""")
+tc.assertTrue(a.prop_complete().is_maybe())
+tc.assertTrue(spot.is_complete(a))