∀ r1. r1 ∈ st0 → r1 < r0, ∃ r1. r0 < r1, ∀ r. ∃ r0. r < r0 ⊦ ∃ r0. ∀ r1. r1 ∈ st0[r -- sk, val] → r1 < r0
[[CONCRETESIMPRULES : ()], [EXTRATERMS : (r0)]]