| ⊦ inv(ixs + ix ', # x) ∧ precedes∃(ixs + ix ', x) → (∀ n. n ∈ ix → (∃ ix0. # ix0 = # ixs ∧ ascsubseq(ix0 + n, x))) |
n ∈ ix, inv(ixs + ix ', # x), precedes∃(ixs + ix ', x) ⊦ ∃ ix0. # ix0 = # ixs ∧ ascsubseq(ix0 + n ', x)
[Concretesimprules((Csimpnamedseq(list,indexseq,Last, ⊦ ix + n = ix + n ')))]