Description: Implicit substitution of a class for a setvar variable. (Contributed by NM, 9-Sep-1993)
Ref | Expression | ||
---|---|---|---|
Hypotheses | vtocle.1 | ⊢ 𝐴 ∈ V | |
vtocle.2 | ⊢ ( 𝑥 = 𝐴 → 𝜑 ) | ||
Assertion | vtocle | ⊢ 𝜑 |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | vtocle.1 | ⊢ 𝐴 ∈ V | |
2 | vtocle.2 | ⊢ ( 𝑥 = 𝐴 → 𝜑 ) | |
3 | 2 | vtocleg | ⊢ ( 𝐴 ∈ V → 𝜑 ) |
4 | 1 3 | ax-mp | ⊢ 𝜑 |