| st -- r = st0 -- r, eqex(st0[rk, val], st1, r), eqex(st0, st, r), eqex(st1, st0[rk, val], r) ⊦ st[rk, val] -- r = st1 -- r |
⊦ eqex(st, st0, r) ↔ st -- r = st0 -- r
st -- r = st0 -- r, st0[rk, val] -- r = st1 -- r, eqex(st0, st, r), eqex(st1, st0[rk, val], r) ⊦ st[rk, val] -- r = st1 -- r
[[CONCRETESIMPRULES : ()], [EXTRATERMS : (r, st1, st0[rk, val])]]