Metamath Proof Explorer


Theorem bnj422

Description: /\ -manipulation. (Contributed by Jonathan Ben-Naim, 3-Jun-2011) (Proof shortened by Andrew Salmon, 14-Jun-2011) (New usage is discouraged.)

Ref Expression
Assertion bnj422 ( ( 𝜑𝜓𝜒𝜃 ) ↔ ( 𝜒𝜃𝜑𝜓 ) )

Proof

Step Hyp Ref Expression
1 bnj345 ( ( 𝜑𝜓𝜒𝜃 ) ↔ ( 𝜃𝜑𝜓𝜒 ) )
2 bnj345 ( ( 𝜃𝜑𝜓𝜒 ) ↔ ( 𝜒𝜃𝜑𝜓 ) )
3 1 2 bitri ( ( 𝜑𝜓𝜒𝜃 ) ↔ ( 𝜒𝜃𝜑𝜓 ) )