Metamath Proof Explorer


Theorem ee011

Description: e011 without virtual deductions. (Contributed by Alan Sare, 25-Jul-2011) (Proof modification is discouraged.) (New usage is discouraged.)

Ref Expression
Hypotheses ee011.1 ⊢ φ
ee011.2 ⊢ ψ → χ
ee011.3 ⊢ ψ → θ
ee011.4 ⊢ φ → χ → θ → τ
Assertion ee011 ⊢ ψ → τ

Proof

Step Hyp Ref Expression
1 ee011.1 ⊢ φ
2 ee011.2 ⊢ ψ → χ
3 ee011.3 ⊢ ψ → θ
4 ee011.4 ⊢ φ → χ → θ → τ
5 1 a1i ⊢ ψ → φ
6 5 2 3 4 syl3c ⊢ ψ → τ