| 0 ≤ i0, is_indexkey(sk) ⊦ sk = 0 ', (addarray(r, ty, 1 + i0, st)[r -- sk]) = (addarray(r, ty, val ' + mklist(initial_value(ty), i→n(i0)), st)[r -- sk]), sk = _length, sk = _type |
⊦ is_indexkey(sk) ↔ (∃ i. sk = i ')
0 ≤ i0, ∃ i. sk = i ' ⊦ sk = 0 ', (addarray(r, ty, 1 + i0, st)[r -- sk]) = (addarray(r, ty, val ' + mklist(initial_value(ty), i→n(i0)), st)[r -- sk]), sk = _length, sk = _type
[[CONCRETESIMPRULES : ()], [EXTRATERMS : (sk)]]