From 0ab331d047f53e8fd8fa8a2a0ff6d2b1b0b3a52d Mon Sep 17 00:00:00 2001
From: Jiri Pittner <jiri@pittnerovi.com>
Date: Thu, 29 Jan 2026 13:48:45 +0100
Subject: [PATCH] tensor: announce subindex() in tensor.h

---
 tensor.h | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/tensor.h b/tensor.h
index 4680e5b..52cb35f 100644
--- a/tensor.h
+++ b/tensor.h
@@ -231,6 +231,9 @@ int flatposition(int group, int index, const NRVec<INDEXGROUP> &shape);
 int flatposition(const INDEX &i, const NRVec<INDEXGROUP> &shape); //position of that index in FLATINDEX
 INDEX indexposition(int flatindex, const NRVec<INDEXGROUP> &shape); //inverse to flatposition
 
+LA_largeindex subindex(int *sign, const INDEXGROUP &g, const NRVec<LA_index> &I); //index of one subgroup
+NRVec<LA_index>  inverse_subindex(const INDEXGROUP &g, LA_largeindex s);
+
 
 //useful for negative offsets and 0 index excluded
 bool zero_in_index(const FLATINDEX &);