Description: The value of the second Gödel operation. (Contributed by BTernaryTau, 18-Oct-2026)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | gdlop2fv.1 | ⊢ ( 𝜑 → 𝐴 ∈ 𝑉 ) | |
| gdlop2fv.2 | ⊢ ( 𝜑 → 𝐵 ∈ 𝑊 ) | ||
| Assertion | gdlop2fv | ⊢ ( 𝜑 → ( ℱ2 ‘ 〈 𝐴 , 𝐵 〉 ) = ( 𝐴 ∩ E ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | gdlop2fv.1 | ⊢ ( 𝜑 → 𝐴 ∈ 𝑉 ) | |
| 2 | gdlop2fv.2 | ⊢ ( 𝜑 → 𝐵 ∈ 𝑊 ) | |
| 3 | 1 | elexd | ⊢ ( 𝜑 → 𝐴 ∈ V ) |
| 4 | 2 | elexd | ⊢ ( 𝜑 → 𝐵 ∈ V ) |
| 5 | inex1g | ⊢ ( 𝐴 ∈ 𝑉 → ( 𝐴 ∩ E ) ∈ V ) | |
| 6 | 1 5 | syl | ⊢ ( 𝜑 → ( 𝐴 ∩ E ) ∈ V ) |
| 7 | ineq1 | ⊢ ( 𝐴 = 𝑥 → ( 𝐴 ∩ E ) = ( 𝑥 ∩ E ) ) | |
| 8 | 7 | adantl | ⊢ ( ( 𝜑 ∧ 𝐴 = 𝑥 ) → ( 𝐴 ∩ E ) = ( 𝑥 ∩ E ) ) |
| 9 | eqidd | ⊢ ( ( 𝜑 ∧ 𝐵 = 𝑦 ) → ( 𝐴 ∩ E ) = ( 𝐴 ∩ E ) ) | |
| 10 | df-gdlop2 | ⊢ ℱ2 = ( 𝑥 ∈ V , 𝑦 ∈ V ↦ ( 𝑥 ∩ E ) ) | |
| 11 | 3 4 6 8 9 10 | mpofvop2d | ⊢ ( 𝜑 → ( ℱ2 ‘ 〈 𝐴 , 𝐵 〉 ) = ( 𝐴 ∩ E ) ) |