Metamath Proof Explorer


Theorem ee012

Description: e012 without virtual deductions. (Contributed by Alan Sare, 14-Jul-2011) (Proof modification is discouraged.) (New usage is discouraged.)

Ref Expression
Hypotheses ee012.1 𝜑
ee012.2 ( 𝜓𝜒 )
ee012.3 ( 𝜓 → ( 𝜃𝜏 ) )
ee012.4 ( 𝜑 → ( 𝜒 → ( 𝜏𝜂 ) ) )
Assertion ee012 ( 𝜓 → ( 𝜃𝜂 ) )

Proof

Step Hyp Ref Expression
1 ee012.1 𝜑
2 ee012.2 ( 𝜓𝜒 )
3 ee012.3 ( 𝜓 → ( 𝜃𝜏 ) )
4 ee012.4 ( 𝜑 → ( 𝜒 → ( 𝜏𝜂 ) ) )
5 1 a1i ( 𝜃𝜑 )
6 5 a1i ( 𝜓 → ( 𝜃𝜑 ) )
7 2 a1d ( 𝜓 → ( 𝜃𝜒 ) )
8 6 7 3 4 ee222 ( 𝜓 → ( 𝜃𝜂 ) )