From c5746ef5cf1d9d939b5ddd1c987550c22c1c23df Mon Sep 17 00:00:00 2001
From: Antoine Martin <amartin@lrde.epita.fr>
Date: Thu, 13 Mar 2025 08:47:41 +0100
Subject: [PATCH] expansions: fix bogus false pairs in linear forms

---
 spot/tl/expansions2.cc | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/spot/tl/expansions2.cc b/spot/tl/expansions2.cc
index 96f970a94..c40298d7f 100644
--- a/spot/tl/expansions2.cc
+++ b/spot/tl/expansions2.cc
@@ -711,7 +711,10 @@ namespace spot
                         if ((li & kj) != bddfalse)
                           res.push_back({li & kj, fj});
                   }
-                res.push_back({li, formula::Fusion({ei, F})});
+
+                formula ei_fusion_F = formula::Fusion({ei, F});
+                if (!ei_fusion_F.is(op::ff))
+                  res.push_back({li, ei_fusion_F});
               }
 
             finalize(res, opts, d, seen);