⊦ st ≠ ∅ → st.min = st.keys.min
st[a, d] ≠ ∅ ⊦ st[a, d].keys.min = st.min, a = st[a, d].keys.min
Used simplifier rules: neq: ⊦ st[a, d] ≠ ∅; from specification store Used terms: st[a, d]