From a63fcd9b5610f2dcedf9a3d98297b51199212013 Mon Sep 17 00:00:00 2001
From: zanderbyte-certora <zanderbyte@certora.com>
Date: Tue, 29 Jul 2025 10:48:59 +0300
Subject: [PATCH] Add mutation 001: accumulateFlows off-by-one

---
 .../mutations/001_accumulateFlows_off_by_one.patch  | 13 +++++++++++++
 1 file changed, 13 insertions(+)
 create mode 100644 certora/mutations/001_accumulateFlows_off_by_one.patch

diff --git a/certora/mutations/001_accumulateFlows_off_by_one.patch b/certora/mutations/001_accumulateFlows_off_by_one.patch
new file mode 100644
index 0000000..538be7d
--- /dev/null
+++ b/certora/mutations/001_accumulateFlows_off_by_one.patch
@@ -0,0 +1,13 @@
+diff --git a/contracts/vault/Accounts.sol b/contracts/vault/Accounts.sol
+index 3066e7d..c93554d 100644
+--- a/contracts/vault/Accounts.sol
++++ b/contracts/vault/Accounts.sol
+@@ -81,7 +81,7 @@ library Accounts {
+     Timestamp timestamp
+   ) internal pure {
+     Duration duration = account.flow.updated.until(timestamp);
+-    account.balance.available -= account.flow.outgoing.accumulate(duration);
++    account.balance.available -= account.flow.outgoing.accumulate(duration) + 1;
+     account.balance.designated += account.flow.incoming.accumulate(duration);
+     account.flow.updated = timestamp;
+   }