This is an inofficial mirror of http://metamath.tirix.org for personal testing of a visualizer extension only.
Description: An operation value is a member of the image plus null. (Contributed by Thierry Arnoux, 25-Jun-2019)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | ovima0 | ⊢ ( ( 𝑋 ∈ 𝐴 ∧ 𝑌 ∈ 𝐵 ) → ( 𝑋 𝑅 𝑌 ) ∈ ( ( 𝑅 “ ( 𝐴 × 𝐵 ) ) ∪ { ∅ } ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | simpr | ⊢ ( ( ( 𝑋 ∈ 𝐴 ∧ 𝑌 ∈ 𝐵 ) ∧ ( 𝑋 𝑅 𝑌 ) = ∅ ) → ( 𝑋 𝑅 𝑌 ) = ∅ ) | |
| 2 | ssun2 | ⊢ { ∅ } ⊆ ( ( 𝑅 “ ( 𝐴 × 𝐵 ) ) ∪ { ∅ } ) | |
| 3 | 0ex | ⊢ ∅ ∈ V | |
| 4 | 3 | snid | ⊢ ∅ ∈ { ∅ } |
| 5 | 2 4 | sselii | ⊢ ∅ ∈ ( ( 𝑅 “ ( 𝐴 × 𝐵 ) ) ∪ { ∅ } ) |
| 6 | 1 5 | eqeltrdi | ⊢ ( ( ( 𝑋 ∈ 𝐴 ∧ 𝑌 ∈ 𝐵 ) ∧ ( 𝑋 𝑅 𝑌 ) = ∅ ) → ( 𝑋 𝑅 𝑌 ) ∈ ( ( 𝑅 “ ( 𝐴 × 𝐵 ) ) ∪ { ∅ } ) ) |
| 7 | ssun1 | ⊢ ( 𝑅 “ ( 𝐴 × 𝐵 ) ) ⊆ ( ( 𝑅 “ ( 𝐴 × 𝐵 ) ) ∪ { ∅ } ) | |
| 8 | df-ov | ⊢ ( 𝑋 𝑅 𝑌 ) = ( 𝑅 ‘ 〈 𝑋 , 𝑌 〉 ) | |
| 9 | opelxpi | ⊢ ( ( 𝑋 ∈ 𝐴 ∧ 𝑌 ∈ 𝐵 ) → 〈 𝑋 , 𝑌 〉 ∈ ( 𝐴 × 𝐵 ) ) | |
| 10 | 8 | eqeq1i | ⊢ ( ( 𝑋 𝑅 𝑌 ) = ∅ ↔ ( 𝑅 ‘ 〈 𝑋 , 𝑌 〉 ) = ∅ ) |
| 11 | 10 | notbii | ⊢ ( ¬ ( 𝑋 𝑅 𝑌 ) = ∅ ↔ ¬ ( 𝑅 ‘ 〈 𝑋 , 𝑌 〉 ) = ∅ ) |
| 12 | 11 | biimpi | ⊢ ( ¬ ( 𝑋 𝑅 𝑌 ) = ∅ → ¬ ( 𝑅 ‘ 〈 𝑋 , 𝑌 〉 ) = ∅ ) |
| 13 | eliman0 | ⊢ ( ( 〈 𝑋 , 𝑌 〉 ∈ ( 𝐴 × 𝐵 ) ∧ ¬ ( 𝑅 ‘ 〈 𝑋 , 𝑌 〉 ) = ∅ ) → ( 𝑅 ‘ 〈 𝑋 , 𝑌 〉 ) ∈ ( 𝑅 “ ( 𝐴 × 𝐵 ) ) ) | |
| 14 | 9 12 13 | syl2an | ⊢ ( ( ( 𝑋 ∈ 𝐴 ∧ 𝑌 ∈ 𝐵 ) ∧ ¬ ( 𝑋 𝑅 𝑌 ) = ∅ ) → ( 𝑅 ‘ 〈 𝑋 , 𝑌 〉 ) ∈ ( 𝑅 “ ( 𝐴 × 𝐵 ) ) ) |
| 15 | 8 14 | eqeltrid | ⊢ ( ( ( 𝑋 ∈ 𝐴 ∧ 𝑌 ∈ 𝐵 ) ∧ ¬ ( 𝑋 𝑅 𝑌 ) = ∅ ) → ( 𝑋 𝑅 𝑌 ) ∈ ( 𝑅 “ ( 𝐴 × 𝐵 ) ) ) |
| 16 | 7 15 | sselid | ⊢ ( ( ( 𝑋 ∈ 𝐴 ∧ 𝑌 ∈ 𝐵 ) ∧ ¬ ( 𝑋 𝑅 𝑌 ) = ∅ ) → ( 𝑋 𝑅 𝑌 ) ∈ ( ( 𝑅 “ ( 𝐴 × 𝐵 ) ) ∪ { ∅ } ) ) |
| 17 | 6 16 | pm2.61dan | ⊢ ( ( 𝑋 ∈ 𝐴 ∧ 𝑌 ∈ 𝐵 ) → ( 𝑋 𝑅 𝑌 ) ∈ ( ( 𝑅 “ ( 𝐴 × 𝐵 ) ) ∪ { ∅ } ) ) |