[Imprint][Data Privacy Statement][E-Mail]

View long theorem info. View the proof. Back to main index. View the specification. View theorem base summary, View theorem base listing, the used properties by spec, the dependency list, the symbol table,

Proof step 12 from proof size-three (previous step)

2 < # s, 2 < #(∅ ++ a ++ b), b ∈ s, a ∈ s, # s ≤ #(∅ ++ a ++ b) ⊦ b = a, ∃ a, b, c. a ∈ s ∧ b ∈ s ∧ c ∈ s ∧ a ≠ b ∧ a ≠ c ∧ b ≠ c

Heuristic weak cut applied rule cut formula

And closed the goal!

Rule argument

fma: b ∈ ∅ ++ a

Additional information

Used simplifier rules: in-04: ⊦ a ∈ ∅ ++ b ↔ a = b;%Size-insert: ⊦ ¬ a ∈ s → #(s ++ a) = # s + 1;%size-one-01: ⊦ #(∅ ++ a) = 1; Used formulas: b ∈ ∅ ++ a