contradiction
case nil
η : Type u_η
dec_η : DecidableEq η
schema : Schema
hdr : Header
nm : η
hpf : HasCol hdr []
cs : List (CertifiedHeader [])
h : HasName nm (map Sigma.fst cs)
⊢ hasNameOfFromCHeaders (HasName.tl h) = hasNameOfFromCHeaders h
no goals