| w ∈ S, w ∈ s, s ⊆ S ⊦ ∀ a. a ∈ (V0 ∪ (S \ s)) ++ w ↔ a ∈ V0 ∪ (S \ (s -- w)), # S = 0, # s = 0, s = ∅, S = ∅, w ∈ V0 |
w ∈ S, w ∈ s, s ⊆ S ⊦ # S = 0, # s = 0, s = ∅, S = ∅, a = w ∨ a ∈ V0 ∪ (S \ s) ↔ a ∈ V0 ∪ (S \ (s -- w)), w ∈ V0
[[CONCRETESIMPRULES : ([CSIMPSEQ : ⊦ a ∈ s ++ b ↔ ¬ ¬ (a = b ∨ a ∈ s)])]]