Description: Deduction form of one negated side of imadisj . (Contributed by Stanislas Polu, 9-Mar-2020)
| Ref | Expression | ||
|---|---|---|---|
| Hypothesis | imadisjlnd.1 | ⊢ ( 𝜑 → ( dom 𝐴 ∩ 𝐵 ) ≠ ∅ ) | |
| Assertion | imadisjlnd | ⊢ ( 𝜑 → ( 𝐴 “ 𝐵 ) ≠ ∅ ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | imadisjlnd.1 | ⊢ ( 𝜑 → ( dom 𝐴 ∩ 𝐵 ) ≠ ∅ ) | |
| 2 | imadisj | ⊢ ( ( 𝐴 “ 𝐵 ) = ∅ ↔ ( dom 𝐴 ∩ 𝐵 ) = ∅ ) | |
| 3 | 2 | biimpi | ⊢ ( ( 𝐴 “ 𝐵 ) = ∅ → ( dom 𝐴 ∩ 𝐵 ) = ∅ ) |
| 4 | 3 | necon3i | ⊢ ( ( dom 𝐴 ∩ 𝐵 ) ≠ ∅ → ( 𝐴 “ 𝐵 ) ≠ ∅ ) |
| 5 | 1 4 | syl | ⊢ ( 𝜑 → ( 𝐴 “ 𝐵 ) ≠ ∅ ) |