| st ⊆ st0 ⊦ st[a, d][a0, d0] ⊆ st0[a, d][a0, d0] |
⊦ st1 ⊆ st2 ↔ (∀ a. a ∈ st1 → a ∈ st2 ∧ st1[a] = st2[a])
st ⊆ st0 ⊦ ∀ a1. a1 ∈ st[a, d][a0, d0] → a1 ∈ st0[a, d][a0, d0] ∧ st[a, d][a0, d0][a1] = st0[a, d][a0, d0][a1]
Used terms: st0[a, d][a0, d0], st[a, d][a0, d0]