From 57d826d7e1fae089a3ec61da60d6f1ca1a4e49d2 Mon Sep 17 00:00:00 2001
From: Tom Smeding <tom@tomsmeding.com>
Date: Sat, 26 Oct 2024 21:28:48 +0200
Subject: Fix EIdx derivative

---
 src/CHAD.hs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/CHAD.hs b/src/CHAD.hs
index dda434c..8319080 100644
--- a/src/CHAD.hs
+++ b/src/CHAD.hs
@@ -1090,7 +1090,7 @@ drev des = \case
         (EIdx ext (EVar ext (STArr n (d1 eltty)) (IS (IS IZ)))
                   (EVar ext (tTup (sreplicate n tIx)) IZ))
         sub
-        (ELet ext (EBuild ext n (EVar ext (tTup (sreplicate n tIx)) (IS IZ)) $
+        (ELet ext (EBuild ext n (EVar ext (tTup (sreplicate n tIx)) (IS (IS IZ))) $
                      ECase ext (EOp ext OIf (eidxEq n (EVar ext tIxN IZ) (EVar ext tIxN (IS (IS IZ)))))
                        (EVar ext (d2 eltty) (IS (IS IZ)))
                        (EZero eltty)) $
-- 
cgit v1.2.3-70-g09d2