| mk(rs1, f) = (∅ ++ r)[r, o], rs1 ∩ rs0 = ∅, R[rs0, f, g], ∀ r. r ∈ rs1 → g(r) = a ⊦ r = null, (r ==>_ * R)[rs1 ∪ rs0, f, g], r ==>_[rs1, f, g] |
mk(rs1, f) = (∅ ++ r)[r, o], rs1 ∩ rs0 = ∅, R[rs0, f, g], ∀ r. r ∈ rs1 → g(r) = a ⊦ r = null, r ==>_[rs1, f, g], (r ==>_ * R)[rs1 ∪ rs0, f, g]