Fix index in truncation

16 jobs for feature/semilinearfunctional in 9 minutes and 26 seconds (queued for 2 seconds)
latest
Status Name Job ID Coverage
  Test
passed dune:git clang C++17 #139303

00:06:15

passed dune:git clang C++17 with examples #139305

00:09:25

passed dune:git gcc-8 C++17 #139304

00:08:15

passed dune:git gcc-8 C++17 with examples #139306

00:05:06

failed dune:git clang C++17 #138826

00:03:45

failed dune:git clang C++17 #138766

00:01:16

failed dune:git clang C++17 #138367

00:02:49

failed dune:git clang C++17 with examples #138828

00:06:20

failed dune:git clang C++17 with examples #138768

00:01:54

failed dune:git clang C++17 with examples #138369

00:01:57

failed dune:git gcc-8 C++17 #138767

00:01:37

failed dune:git gcc-8 C++17 #138368

00:03:23

failed dune:git gcc-8 C++17 #138827

00:04:18

failed dune:git gcc-8 C++17 with examples #138370

00:07:28

failed dune:git gcc-8 C++17 with examples #138829

00:02:35

failed dune:git gcc-8 C++17 with examples #138769

00:02:41