| unchanged(str, refs .first, st, st1), junkrefs(str, refs, st1[refs .first -- _type] .type, st1) ⊦ refs = [], junkref(str, refs .first, st) |
refs = r + refs0, unchanged(str, r, st, st1), junkrefs(str, refs, st1[r -- _type] .type, st1) ⊦ refs = [], junkref(str, r, st)
[[CONCRETESIMPRULES : ([CSIMPELIM : refs ≠ [] ⊦ r = refs .first ∧ refs0 = refs .rest ↔ refs = r + refs0])], [EXTRATERMS : (refs, r, refs0)]]