| a ∈ st0, (a0 ∈ st1 ↔ a0 ∈ st0 -- a) → # st1 = # st0 - 1, ∀ st0. (∀ a. a ∈ st1 ↔ a ∈ st0) → # st1 = # st0, ∀ a0. a0 ∈ st1[a, d] ↔ a0 ∈ st0 ⊦ # st1 + 1 = # st0, a ∈ st1 |
# st0 = m + 1, a ∈ st0, (a0 ∈ st1 ↔ a0 ∈ st0 -- a) → # st1 = m, ∀ a0. a0 ∈ st1[a, d] ↔ a0 ∈ st0, ∀ st0. (∀ a. a ∈ st1 ↔ a ∈ st0) → # st1 = # st0 ⊦ # st0 = 0, # st1 + 1 = # st0, a ∈ st1
Used simplifier rules: empty: ⊦ # st = 0 ↔ st = ∅;%Size-empty: ⊦ # ∅ = 0;%In-empty: ⊦ ¬ a ∈ ∅;% ⊦ m + 1 ≠ 0; (s)%a: ⊦ (m + n0) + n1 = m + n0 + n1; from specification nat-basic%c: ⊦ m + n = n + m; from specification nat-basic%n ≠ 0 ⊦ m = n - 1 ↔ n = m + 1; (elim) Used terms: # st0, m