From 6dbdd2396d2c22eb68c2ab48a8b75af90d2516b8 Mon Sep 17 00:00:00 2001
From: Bokuan Li <bokuan.li@mail.mcgill.ca>
Date: Sun, 18 Oct 2026 19:57:47 -0400
Subject: [PATCH] Fixed sign error.

---
 src/op/system/os.tex | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/op/system/os.tex b/src/op/system/os.tex
index 90bf729..590bfa9 100644
--- a/src/op/system/os.tex
+++ b/src/op/system/os.tex
@@ -33,7 +33,7 @@
 
     Assume without loss of generality that $\seq{x_n} \subset S_{sa}$, so that $\sigma_A(x_n) \subset \real$ for all $n \in \natp$. By \hyperref[upper semicontinuity of the spectrum]{proposition:spectrum-continuous}, $\lim_{n \to \infty}\inf(\sigma_A(x_n)) \ge 0$. Therefore
     \[
-    x = \limv{n}x_n = \limv{n}[x_n + \inf(\sigma_A(x_n)) \wedge 0] \in \ol{S_+}
+    x = \limv{n}x_n = \limv{n}[x_n - \inf(\sigma_A(x_n)) \wedge 0] \in \ol{S_+}
     \]
 
     by \autoref{corollary:spectrum-characterisation-iff}.