Merge branch 'master' into issue_660

Author: tturocy

.github/workflows/lint.yml

@@ -11,7 +11,7 @@ jobs:
     steps:
       - uses: actions/checkout@v6
       - name: Run clang-format style check for C/C++
-        uses: jidicula/clang-format-action@v4.16.0
+        uses: jidicula/clang-format-action@v4.17.0
         with:
           clang-format-version: '17'
           check-path: 'src'

.github/workflows/osxbinary.yml

@@ -31,7 +31,7 @@ jobs:
       - run: make
       - run: sudo make install
       - run: make osx-dmg
-      - uses: actions/upload-artifact@v6
+      - uses: actions/upload-artifact@v7
         with:
           name: artifact-osx-14
           path: "*.dmg"

.github/workflows/tools.yml

@@ -68,7 +68,7 @@ jobs:
           cp gambit* installer
           "${WIX}bin/candle" build_support/msw/gambit.wxs
           "${WIX}bin/light" -ext WixUIExtension gambit.wixobj
-      - uses: actions/upload-artifact@v6
+      - uses: actions/upload-artifact@v7
         with:
           name: artifact-msw
           path: "*.msi"

.github/workflows/wheels.yml

@@ -27,6 +27,6 @@ jobs:
           python -m cibuildwheel --output-dir wheelhouse/
         env:
           CIBW_SKIP: "pp*"
-      - uses: actions/upload-artifact@v6
+      - uses: actions/upload-artifact@v7
         with:
           path: ./wheelhouse/*.whl

ChangeLog

@@ -5,17 +5,27 @@
 ### Changed
 - `Game.comment` has been renamed to `Game.description`
 
+### Added
+- Implement linear-time algorithm to find all root nodes of proper subgames, using an adaptation of
+  Tarjan's (1974) algorithm for finding bridges in an undirected graph.  Subgame roots are cached so
+  subsequent lookup is constant-time (if the game is unchanged).  (#584)
+
 ### Fixed
 - `enumpoly` would take a very long time on some supports where an equilibrium is located on the
   boundary of the projected game.  Search is now restricted to the interior of the space ruling
   these out; these will always be found by another projection.  (#756)
+- In the graphical interface, the logit correspondence display would fail and terminate the program
+  on very small (<10^{-300}) probabilities.
+- The new subgame root computation fixes a bug which failed to detect subgames where the subgame
+  root node is a member of an absent-minded infoset.  (#584)
+- Removed spurious warning in graphical interface when loading file as a command-line argument
+  (or also by clicking on a file in MSW, as that uses the command-line mechanism).  (#801)
 
 ## [16.5.1] - unreleased
 
 ### Fixed
 - `Game.reveal` raised a null pointer access exception or dumped core in some cases (#749)
 
-
 ## [16.5.0] - 2026-01-05
 
 ### Fixed

Makefile.am

@@ -85,7 +85,6 @@ EXTRA_DIST = \
 	src/gui/bitmaps/prev.xpm \
 	src/gui/bitmaps/print.xpm \
 	src/gui/bitmaps/profiles.xpm \
-	src/gui/bitmaps/redo.xpm \
 	src/gui/bitmaps/saveas.xpm \
 	src/gui/bitmaps/savedata.xpm \
 	src/gui/bitmaps/save.xpm \
@@ -94,7 +93,6 @@ EXTRA_DIST = \
 	src/gui/bitmaps/tobegin.xpm \
 	src/gui/bitmaps/toend.xpm \
 	src/gui/bitmaps/tree.xpm \
-	src/gui/bitmaps/undo.xpm \
 	src/gui/bitmaps/zoomfit.xpm \
 	src/gui/bitmaps/zoomin.xpm \
 	src/gui/bitmaps/zoomout.xpm \
@@ -171,8 +169,6 @@ EXTRA_DIST = \
 	contrib/games/palf2.efg \
 	contrib/games/palf3.efg \
 	contrib/games/palf.efg \
-	contrib/games/poker2.efg \
-	contrib/games/poker.efg \
 	contrib/games/pvw2.efg \
 	contrib/games/pvw.efg \
 	contrib/games/sh3.efg \
@@ -188,6 +184,7 @@ EXTRA_DIST = \
 	contrib/games/work1.efg \
 	contrib/games/work2.efg \
 	contrib/games/work3.efg \
+	contrib/games/2smp.efg \
 	contrib/games/2x2a.nfg \
 	contrib/games/2x2const.nfg \
 	contrib/games/2x2.nfg \
@@ -222,7 +219,6 @@ EXTRA_DIST = \
 	contrib/games/perfect1.nfg \
 	contrib/games/perfect2.nfg \
 	contrib/games/perfect3.nfg \
-	contrib/games/poker.nfg \
 	contrib/games/sh3.nfg \
 	contrib/games/stengel.nfg \
 	contrib/games/sww1.nfg \
@@ -235,11 +231,15 @@ EXTRA_DIST = \
 	contrib/games/yamamoto.nfg \
 	contrib/games/zero.nfg \
 	src/README.rst \
-	catalog/2smp.efg \
+	catalog/bagwell1995.efg \
+	catalog/myerson1991/fig2_1.efg \
 	catalog/myerson1991/fig4_2.efg \
+	catalog/reiley2008/fig1.efg \
 	catalog/selten1975/fig1.efg \
 	catalog/selten1975/fig2.efg \
-	catalog/selten1975/fig3.efg
+	catalog/selten1975/fig3.efg \
+	catalog/watson2013/exercise29_6.efg \
+	catalog/watson2013/fig29_1.efg
 
 core_SOURCES = \
     src/core/core.h \

catalog/bagwell1995.efg

@@ -0,0 +1,29 @@
+EFG 2 R "Bagwell (GEB 1995) commitment and (un)observability" { "Player 1" "Player 2" }
+"This is a Stackelberg-type game with imperfectly observed commitment, following the
+analysis of Bagwell [^Bag1995].  The outcomes and payoffs are the same as in Bagwell's
+model.  This example sets the probability that the follower 'correctly' observes the
+leader's action as .99 (99/100).  The key result is that the only pure-strategy
+equilibrium that survives if observability is imperfect is the one in which players
+choose the actions that would form an equilibrium if the game was a *simultaneous-move*
+game.  There is an equilibrium in which the 'Stackelberg' action is played with high
+probability, but strictly less than one.
+
+[^Bag1995]: Bagwell, Kyle (1995)  Commitment and observability in games.
+    _Games and Economic Behavior_ 8: 271-280.
+"
+
+p "" 1 1 "" { "S" "C" } 0
+c "" 1 "" { "s" 99/100 "c" 1/100 } 0
+p "" 2 1 "" { "S" "C" } 0
+t "" 1 "SS" { 5, 2 }
+t "" 2 "SC" { 3, 1 }
+p "" 2 2 "" { "S" "C" } 0
+t "" 1 "SS" { 5, 2 }
+t "" 2 "SC" { 3, 1 }
+c "" 2 "" { "s" 1/100 "c" 99/100 } 0
+p "" 2 1 "" { "S" "C" } 0
+t "" 3 "CS" { 6, 3 }
+t "" 4 "CC" { 4, 4 }
+p "" 2 2 "" { "S" "C" } 0
+t "" 3 "CS" { 6, 3 }
+t "" 4 "CC" { 4, 4 }

catalog/myerson1991/fig2_1.efg

@@ -0,0 +1,30 @@
+EFG 2 R "A simple Poker game" { "Fred" "Alice" }
+"This is a simple game of one-card poker from Myerson [^Mye91], used as the
+introductory example for game models.
+
+Note that as specified in the text, the game has the slightly unusual feature
+that folding with the high (red) card results in the player winning rather than
+losing.
+
+See also
+--------
+reiley2008/fig1
+   Another one-card poker game where folding with the high card is a loss rather
+   than a win.
+
+
+[^Mye1991]: Myerson, Roger B. (1991)  Game Theory: Analysis of Conflict.
+  Cambridge: Harvard University Press.
+"
+
+c "" 1 "" { "Red" 1/2 "Black" 1/2 } 0
+p "" 1 1 "" { "Raise" "Fold" } 0
+p "" 2 1 "" { "Meet" "Pass" } 0
+t "" 1 "Win Big" { 2, -2 }
+t "" 2 "Win" { 1, -1 }
+t "" 2 "Win" { 1, -1 }
+p "" 1 2 "" { "Raise" "Fold" } 0
+p "" 2 1 "" { "Meet" "Pass" } 0
+t "" 3 "Lose Big" { -2, 2 }
+t "" 2 "Win" { 1, -1 }
+t "" 4 "Lose" { -1, 1 }

catalog/reiley2008/fig1.efg

@@ -0,0 +1,24 @@
+EFG 2 R "Stripped-down poker (Reiley et al 2008)" { "Professor" "Student" }
+"This is a one-card poker game used in [^Rei2008] as a teaching exercise.
+
+See also
+--------
+myerson1991/fig2_1
+    Another one-card poker game with slightly different rules.
+
+[^Rei2008]: Reiley, David H., Urbancic, Michael B, and Walker, Mark. (2008)
+    Stripped-Down Poker: A Classroom Game with Signaling and Bluffing.
+    _The Journal of Economic Education_ 4: 323-341.
+"
+
+c "" 1 "" { "King" 1/2 "Queen" 1/2 } 0
+p "" 1 1 "" { "Bet" "Fold" } 0
+p "" 2 1 "" { "Call" "Fold" } 0
+t "" 1 "Professor Wins Big" { 2, -2 }
+t "" 2 "Professor Wins" { 1, -1 }
+t "" 4 "Professor Loses" { -1, 1 }
+p "" 1 2 "" { "Bet" "Fold" } 0
+p "" 2 1 "" { "Call" "Fold" } 0
+t "" 3 "Professor Loses Big" { -2, 2 }
+t "" 2 "Professor Wins" { 1, -1 }
+t "" 4 "Professor Loses" { -1, 1 }

catalog/watson2013/exercise29_6.efg

@@ -0,0 +1,37 @@
+EFG 2 R "Princess Bride signaling game (from Watson)" { "Wesley" "Prince" }
+"This game is Exercise 29.6 from Watson [^Wat13], based on a scene from
+the Rob Reiner film, _The Princess Bride_:
+
+Wesley (the protagonist) confronts the evil prince Humperdinck.  Wesley
+is one of two types: weak or strong.  Wesley knows whether he is weak or
+strong, but the prince only knows that he is weak with probability 1/2 and
+strong with probability 1/2.  Wesley is lying in a bed in the prince's
+castle when the prince enters the room.  Wesley decides whether to get out
+of bed or stay in bed.  The prince observes Wesley's action but does not
+observe Wesley's type.  The prince then decides whether to fight or
+surrender to Wesley.  The payoffs are such that the prince prefers to fight
+only with the weak Wesley, because otherwise the prince is an inferior
+swordsman.  Also, the weak Wesley must pay a cost to get out of bed.
+
+In the game in this file, the cost the weak Wesley pays to get out of bed
+is set to 2.
+
+[^Wat13]: Watson, Joel.  (2013)  Strategy: An Introduction to Game Theory,
+   third edition.  W. W. Norton & Company.
+"
+
+c "" 1 "" { "Strong" 1/2 "Weak" 1/2 } 0
+p "" 1 1 "" { "Up" "Stay" } 0
+p "" 2 1 "" { "Surrender" "Fight" } 0
+t "" 1 "Outcome1" { 1, 0 }
+t "" 2 "Outcome2" { 0, -2 }
+p "" 2 2 "" { "Surrender" "Fight" } 0
+t "" 3 "Outcome3" { 1, 0 }
+t "" 4 "Outcome4" { 0, -2 }
+p "" 1 2 "" { "Up" "Stay" } 0
+p "" 2 1 "" { "Surrender" "Fight" } 0
+t "" 5 "Outcome5" { -1, 0 }
+t "" 6 "Outcome6" { -3, 1 }
+p "" 2 2 "" { "Surrender" "Fight" } 0
+t "" 7 "Outcome7" { 1, 0 }
+t "" 8 "Outcome8" { -1, 1 }