Metamath Proof Explorer


Theorem ifpnannanb

Description: Factor conditional logic operator over nand in terms 2 and 3. (Contributed by RP, 21-Apr-2020)

Ref Expression
Assertion ifpnannanb ( if- ( 𝜑 , ( 𝜓𝜒 ) , ( 𝜃𝜏 ) ) ↔ ( if- ( 𝜑 , 𝜓 , 𝜃 ) ⊼ if- ( 𝜑 , 𝜒 , 𝜏 ) ) )

Proof

Step Hyp Ref Expression
1 df-nan ( ( 𝜓𝜒 ) ↔ ¬ ( 𝜓𝜒 ) )
2 df-nan ( ( 𝜃𝜏 ) ↔ ¬ ( 𝜃𝜏 ) )
3 ifpbi23 ( ( ( ( 𝜓𝜒 ) ↔ ¬ ( 𝜓𝜒 ) ) ∧ ( ( 𝜃𝜏 ) ↔ ¬ ( 𝜃𝜏 ) ) ) → ( if- ( 𝜑 , ( 𝜓𝜒 ) , ( 𝜃𝜏 ) ) ↔ if- ( 𝜑 , ¬ ( 𝜓𝜒 ) , ¬ ( 𝜃𝜏 ) ) ) )
4 1 2 3 mp2an ( if- ( 𝜑 , ( 𝜓𝜒 ) , ( 𝜃𝜏 ) ) ↔ if- ( 𝜑 , ¬ ( 𝜓𝜒 ) , ¬ ( 𝜃𝜏 ) ) )
5 ifpananb ( if- ( 𝜑 , ( 𝜓𝜒 ) , ( 𝜃𝜏 ) ) ↔ ( if- ( 𝜑 , 𝜓 , 𝜃 ) ∧ if- ( 𝜑 , 𝜒 , 𝜏 ) ) )
6 5 notbii ( ¬ if- ( 𝜑 , ( 𝜓𝜒 ) , ( 𝜃𝜏 ) ) ↔ ¬ ( if- ( 𝜑 , 𝜓 , 𝜃 ) ∧ if- ( 𝜑 , 𝜒 , 𝜏 ) ) )
7 ifpnotnotb ( if- ( 𝜑 , ¬ ( 𝜓𝜒 ) , ¬ ( 𝜃𝜏 ) ) ↔ ¬ if- ( 𝜑 , ( 𝜓𝜒 ) , ( 𝜃𝜏 ) ) )
8 df-nan ( ( if- ( 𝜑 , 𝜓 , 𝜃 ) ⊼ if- ( 𝜑 , 𝜒 , 𝜏 ) ) ↔ ¬ ( if- ( 𝜑 , 𝜓 , 𝜃 ) ∧ if- ( 𝜑 , 𝜒 , 𝜏 ) ) )
9 6 7 8 3bitr4i ( if- ( 𝜑 , ¬ ( 𝜓𝜒 ) , ¬ ( 𝜃𝜏 ) ) ↔ ( if- ( 𝜑 , 𝜓 , 𝜃 ) ⊼ if- ( 𝜑 , 𝜒 , 𝜏 ) ) )
10 4 9 bitri ( if- ( 𝜑 , ( 𝜓𝜒 ) , ( 𝜃𝜏 ) ) ↔ ( if- ( 𝜑 , 𝜓 , 𝜃 ) ⊼ if- ( 𝜑 , 𝜒 , 𝜏 ) ) )