Metamath Proof Explorer

Theorem bnj255

Description: /\ -manipulation. (Contributed by Jonathan Ben-Naim, 3-Jun-2011) (New usage is discouraged.)

Ref Expression
Assertion bnj255 ⊢ φ ∧ ψ ∧ χ ∧ θ ↔ φ ∧ ψ ∧ χ ∧ θ

Proof

Step Hyp Ref Expression
1 bnj251 ⊢ φ ∧ ψ ∧ χ ∧ θ ↔ φ ∧ ψ ∧ χ ∧ θ
2 3anass ⊢ φ ∧ ψ ∧ χ ∧ θ ↔ φ ∧ ψ ∧ χ ∧ θ
3 1 2 bitr4i ⊢ φ ∧ ψ ∧ χ ∧ θ ↔ φ ∧ ψ ∧ χ ∧ θ