Metamath Proof Explorer


Theorem sbcan

Description: Distribution of class substitution over conjunction. (Contributed by NM, 31-Dec-2016) (Revised by NM, 17-Aug-2018)

Ref Expression
Assertion sbcan ( [ 𝐴 / 𝑥 ] ( 𝜑𝜓 ) ↔ ( [ 𝐴 / 𝑥 ] 𝜑[ 𝐴 / 𝑥 ] 𝜓 ) )

Proof

Step Hyp Ref Expression
1 sbcex ( [ 𝐴 / 𝑥 ] ( 𝜑𝜓 ) → 𝐴 ∈ V )
2 sbcex ( [ 𝐴 / 𝑥 ] 𝜓𝐴 ∈ V )
3 2 adantl ( ( [ 𝐴 / 𝑥 ] 𝜑[ 𝐴 / 𝑥 ] 𝜓 ) → 𝐴 ∈ V )
4 dfsbcq2 ( 𝑦 = 𝐴 → ( [ 𝑦 / 𝑥 ] ( 𝜑𝜓 ) ↔ [ 𝐴 / 𝑥 ] ( 𝜑𝜓 ) ) )
5 dfsbcq2 ( 𝑦 = 𝐴 → ( [ 𝑦 / 𝑥 ] 𝜑[ 𝐴 / 𝑥 ] 𝜑 ) )
6 dfsbcq2 ( 𝑦 = 𝐴 → ( [ 𝑦 / 𝑥 ] 𝜓[ 𝐴 / 𝑥 ] 𝜓 ) )
7 5 6 anbi12d ( 𝑦 = 𝐴 → ( ( [ 𝑦 / 𝑥 ] 𝜑 ∧ [ 𝑦 / 𝑥 ] 𝜓 ) ↔ ( [ 𝐴 / 𝑥 ] 𝜑[ 𝐴 / 𝑥 ] 𝜓 ) ) )
8 sban ( [ 𝑦 / 𝑥 ] ( 𝜑𝜓 ) ↔ ( [ 𝑦 / 𝑥 ] 𝜑 ∧ [ 𝑦 / 𝑥 ] 𝜓 ) )
9 4 7 8 vtoclbg ( 𝐴 ∈ V → ( [ 𝐴 / 𝑥 ] ( 𝜑𝜓 ) ↔ ( [ 𝐴 / 𝑥 ] 𝜑[ 𝐴 / 𝑥 ] 𝜓 ) ) )
10 1 3 9 pm5.21nii ( [ 𝐴 / 𝑥 ] ( 𝜑𝜓 ) ↔ ( [ 𝐴 / 𝑥 ] 𝜑[ 𝐴 / 𝑥 ] 𝜓 ) )