| ⊦ all≥(b ' + x, a) ↔ ¬ b < a ∧ all≥(x, a) |
¬(all≥(b ' + x, a) ↔ ¬ b < a ∧ all≥(x, a)) ⊦
| ¬(all≥(b ' + x, a) ↔ ¬ b < a ∧ all≥(x, a)) ⊦ |
⊦ (∀ b0. b0 = b ∨ b0 ∈ x → ¬ b0 < a) ↔ ¬ b < a ∧ (∀ b. b ∈ x → ¬ b < a)
Used simplifier rules: allge-def: ⊦ all≥(x, a) ↔ (∀ b. b ∈ x → ¬ b < a); a: ⊦ (x + y) + z = x + y + z; from specification list ⊦ a ∈ a0 ' + x ↔ a = a0 ∨ a ∈ x; (s)
| ⊦ (∀ b0. b0 = b ∨ b0 ∈ x → ¬ b0 < a) ↔ ¬ b < a ∧ (∀ b. b ∈ x → ¬ b < a) |
b < a ⊦ (∀ b0. b0 = b ∨ b0 ∈ x → ¬ b0 < a) ↔ ¬ b < a ∧ (∀ b. b ∈ x → ¬ b < a)
Used formulas: b < a
| b < a ⊦ (∀ b0. b0 = b ∨ b0 ∈ x → ¬ b0 < a) ↔ ¬ b < a ∧ (∀ b. b ∈ x → ¬ b < a) |
b < a, ∀ b0. b0 = b ∨ b0 ∈ x → ¬ b0 < a ⊦
| b < a, ∀ b0. b0 = b ∨ b0 ∈ x → ¬ b0 < a ⊦ |
Used terms: b
The following image shows the proof tree of sequent calculus. The proved goal is at the bottom. You can click on the nodes to view additional rules. See here for details on colors in a proof tree.