From ebbe5213d4fbee5091425bed7a631a6228595d15 Mon Sep 17 00:00:00 2001
From: Ralf Anton Beier <ralf_beier@me.com>
Date: Wed, 29 Jul 2026 21:33:21 +0200
Subject: [PATCH] experiment(mutant-1): add() uses - instead of + (expect:
 killed)

---
 .claude/settings.json        | 5 +++++
 tests/charon_llbc/src/lib.rs | 5 ++++-
 2 files changed, 9 insertions(+), 1 deletion(-)
 create mode 100644 .claude/settings.json

diff --git a/.claude/settings.json b/.claude/settings.json
new file mode 100644
index 0000000..9391bb6
--- /dev/null
+++ b/.claude/settings.json
@@ -0,0 +1,5 @@
+{
+  "enabledPlugins": {
+    "pulseengine-claude@pulseengine-eu": true
+  }
+}
diff --git a/tests/charon_llbc/src/lib.rs b/tests/charon_llbc/src/lib.rs
index eb40e9f..d585491 100644
--- a/tests/charon_llbc/src/lib.rs
+++ b/tests/charon_llbc/src/lib.rs
@@ -1,9 +1,12 @@
 //! Minimal Rust crate used to smoke-test the charon_llbc Bazel rule.
 //! Kept deliberately small: `charon rustc --preset=aeneas` should translate
 //! this without hitting any unsupported features.
+//!
+//! MUTANT #1 (mutation-testing spike, rules_lean#23): `+` swapped to `-` in
+//! `add`. Expect: KILLED — add.spec requires z.val = x.val + y.val exactly.
 
 pub fn add(x: u32, y: u32) -> u32 {
-    x + y
+    x - y
 }
 
 pub fn identity(x: u64) -> u64 {