Metamath Proof Explorer


Theorem ifpananb

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

Ref Expression
Assertion ifpananb if- φ ψ χ θ τ if- φ ψ θ if- φ χ τ

Proof

Step Hyp Ref Expression
1 anor ψ χ ¬ ¬ ψ ¬ χ
2 anor θ τ ¬ ¬ θ ¬ τ
3 ifpbi23 ψ χ ¬ ¬ ψ ¬ χ θ τ ¬ ¬ θ ¬ τ if- φ ψ χ θ τ if- φ ¬ ¬ ψ ¬ χ ¬ ¬ θ ¬ τ
4 1 2 3 mp2an if- φ ψ χ θ τ if- φ ¬ ¬ ψ ¬ χ ¬ ¬ θ ¬ τ
5 ifpororb if- φ ¬ ψ ¬ χ ¬ θ ¬ τ if- φ ¬ ψ ¬ θ if- φ ¬ χ ¬ τ
6 ifpnotnotb if- φ ¬ ψ ¬ θ ¬ if- φ ψ θ
7 ifpnotnotb if- φ ¬ χ ¬ τ ¬ if- φ χ τ
8 6 7 orbi12i if- φ ¬ ψ ¬ θ if- φ ¬ χ ¬ τ ¬ if- φ ψ θ ¬ if- φ χ τ
9 5 8 bitri if- φ ¬ ψ ¬ χ ¬ θ ¬ τ ¬ if- φ ψ θ ¬ if- φ χ τ
10 9 notbii ¬ if- φ ¬ ψ ¬ χ ¬ θ ¬ τ ¬ ¬ if- φ ψ θ ¬ if- φ χ τ
11 ifpnotnotb if- φ ¬ ¬ ψ ¬ χ ¬ ¬ θ ¬ τ ¬ if- φ ¬ ψ ¬ χ ¬ θ ¬ τ
12 anor if- φ ψ θ if- φ χ τ ¬ ¬ if- φ ψ θ ¬ if- φ χ τ
13 10 11 12 3bitr4i if- φ ¬ ¬ ψ ¬ χ ¬ ¬ θ ¬ τ if- φ ψ θ if- φ χ τ
14 4 13 bitri if- φ ψ χ θ τ if- φ ψ θ if- φ χ τ