spec: <toplevel>
name: size-exgr
seq: # s < # s0 ⊦ ∃ a. a ∈ s0 ∧ ¬ a ∈ s
subst: [s, s0] → [s1, s]
Additional information
Used simplifier rules:
sub-in: ⊦ a ∈ s ∧ s ⊆ s0 → a ∈ s0;%ne-01: ⊦ a ∈ s → s ≠ ∅;%ne-02: ⊦ a ∈ s → (s = ∅ ↔ false);%In-insert: ⊦ a ∈ s ++ b ↔ a = b ∨ a ∈ s;
Used terms: s1, s