| st[n0] = mkblock(x1, lax1, m1), st[n] = mkblock(x0, lax0, m0), n0 ∈ st, n ∈ st, m0 = (as | n).size → m = (as | n).size, ∀ n. n ∈ st → st[n].ref-size = (as | n).size ⊦ m0 = (as | n).size, m1 = (as | n0).size, n0 = n |
st[n] = mkblock(x0, lax0, m0), st[n0] = mkblock(x1, lax1, m1), n ∈ st, n0 ∈ st, ∀ n. n ∈ st → st[n].ref-size = (as | n).size ⊦ m0 = (as | n).size, m1 = (as | n0).size, n0 = n