Function rebind_via 

pub fn rebind_via(
    name: &str,
    from: usize,
    to: usize,
    input: fn(usize) -> String,
) -> String

rebind for a bundle whose layers name their hidden-state input with input — the stacked X/bxo{l-1} of a batch. A per-sequence tensor keeps its sequence suffix (Kc3_s1 at layer 7 is Kc7_s1).