Metamath Proof Explorer


Theorem sbceq1d

Description: Equality theorem for class substitution. (Contributed by Mario Carneiro, 9-Feb-2017) (Revised by NM, 30-Jun-2018)

Ref Expression
Hypothesis sbceq1d.1 φA=B
Assertion sbceq1d φ[˙A/x]˙ψ[˙B/x]˙ψ

Proof

Step Hyp Ref Expression
1 sbceq1d.1 φA=B
2 dfsbcq A=B[˙A/x]˙ψ[˙B/x]˙ψ
3 1 2 syl φ[˙A/x]˙ψ[˙B/x]˙ψ