⊦ eqex(st, st0, r) → eqex(st0, st, r)
eqex(st1, st0, r), eqex(st0, st, r), eqex(st0, st1, r), eqex(st, st0, r) ⊦ eqex(st, st1, r)
[[CONCRETESIMPRULES : ()]]