Metamath Proof Explorer


Theorem rspcdv2

Description: Restricted specialization, using implicit substitution. (Contributed by Stanislas Polu, 9-Mar-2020)

Ref Expression
Hypotheses rspcdv2.1 ( ( 𝜑𝑥 = 𝐴 ) → ( 𝜓𝜒 ) )
rspcdv2.2 ( 𝜑𝐴𝐵 )
rspcdv2.3 ( 𝜑 → ∀ 𝑥𝐵 𝜓 )
Assertion rspcdv2 ( 𝜑𝜒 )

Proof

Step Hyp Ref Expression
1 rspcdv2.1 ( ( 𝜑𝑥 = 𝐴 ) → ( 𝜓𝜒 ) )
2 rspcdv2.2 ( 𝜑𝐴𝐵 )
3 rspcdv2.3 ( 𝜑 → ∀ 𝑥𝐵 𝜓 )
4 2 1 rspcdv ( 𝜑 → ( ∀ 𝑥𝐵 𝜓𝜒 ) )
5 3 4 mpd ( 𝜑𝜒 )