Metamath Proof Explorer


Theorem ee201

Description: e201 without virtual deductions. (Contributed by Alan Sare, 14-Jul-2011) (Proof modification is discouraged.) (New usage is discouraged.)

Ref Expression
Hypotheses ee201.1 ( 𝜑 → ( 𝜓𝜒 ) )
ee201.2 𝜃
ee201.3 ( 𝜑𝜏 )
ee201.4 ( 𝜒 → ( 𝜃 → ( 𝜏𝜂 ) ) )
Assertion ee201 ( 𝜑 → ( 𝜓𝜂 ) )

Proof

Step Hyp Ref Expression
1 ee201.1 ( 𝜑 → ( 𝜓𝜒 ) )
2 ee201.2 𝜃
3 ee201.3 ( 𝜑𝜏 )
4 ee201.4 ( 𝜒 → ( 𝜃 → ( 𝜏𝜂 ) ) )
5 2 a1i ( 𝜓𝜃 )
6 5 a1i ( 𝜑 → ( 𝜓𝜃 ) )
7 3 a1d ( 𝜑 → ( 𝜓𝜏 ) )
8 1 6 7 4 ee222 ( 𝜑 → ( 𝜓𝜂 ) )