Description: Existence of the conditional operator (deduction form). (Contributed by SN, 26-Jul-2024)
Ref | Expression | ||
---|---|---|---|
Hypotheses | ifexd.1 | ⊢ ( 𝜑 → 𝐴 ∈ 𝑉 ) | |
ifexd.2 | ⊢ ( 𝜑 → 𝐵 ∈ 𝑊 ) | ||
Assertion | ifexd | ⊢ ( 𝜑 → if ( 𝜓 , 𝐴 , 𝐵 ) ∈ V ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | ifexd.1 | ⊢ ( 𝜑 → 𝐴 ∈ 𝑉 ) | |
2 | ifexd.2 | ⊢ ( 𝜑 → 𝐵 ∈ 𝑊 ) | |
3 | 1 | elexd | ⊢ ( 𝜑 → 𝐴 ∈ V ) |
4 | 2 | elexd | ⊢ ( 𝜑 → 𝐵 ∈ V ) |
5 | 3 4 | ifcld | ⊢ ( 𝜑 → if ( 𝜓 , 𝐴 , 𝐵 ) ∈ V ) |