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Description: Equality of two operations is determined by their values. (Contributed by NM, 1-Sep-2005)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | eqfnov | ⊢ ( ( 𝐹 Fn ( 𝐴 × 𝐵 ) ∧ 𝐺 Fn ( 𝐶 × 𝐷 ) ) → ( 𝐹 = 𝐺 ↔ ( ( 𝐴 × 𝐵 ) = ( 𝐶 × 𝐷 ) ∧ ∀ 𝑥 ∈ 𝐴 ∀ 𝑦 ∈ 𝐵 ( 𝑥 𝐹 𝑦 ) = ( 𝑥 𝐺 𝑦 ) ) ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | eqfnfv2 | ⊢ ( ( 𝐹 Fn ( 𝐴 × 𝐵 ) ∧ 𝐺 Fn ( 𝐶 × 𝐷 ) ) → ( 𝐹 = 𝐺 ↔ ( ( 𝐴 × 𝐵 ) = ( 𝐶 × 𝐷 ) ∧ ∀ 𝑧 ∈ ( 𝐴 × 𝐵 ) ( 𝐹 ‘ 𝑧 ) = ( 𝐺 ‘ 𝑧 ) ) ) ) | |
| 2 | fveq2 | ⊢ ( 𝑧 = 〈 𝑥 , 𝑦 〉 → ( 𝐹 ‘ 𝑧 ) = ( 𝐹 ‘ 〈 𝑥 , 𝑦 〉 ) ) | |
| 3 | fveq2 | ⊢ ( 𝑧 = 〈 𝑥 , 𝑦 〉 → ( 𝐺 ‘ 𝑧 ) = ( 𝐺 ‘ 〈 𝑥 , 𝑦 〉 ) ) | |
| 4 | 2 3 | eqeq12d | ⊢ ( 𝑧 = 〈 𝑥 , 𝑦 〉 → ( ( 𝐹 ‘ 𝑧 ) = ( 𝐺 ‘ 𝑧 ) ↔ ( 𝐹 ‘ 〈 𝑥 , 𝑦 〉 ) = ( 𝐺 ‘ 〈 𝑥 , 𝑦 〉 ) ) ) |
| 5 | df-ov | ⊢ ( 𝑥 𝐹 𝑦 ) = ( 𝐹 ‘ 〈 𝑥 , 𝑦 〉 ) | |
| 6 | df-ov | ⊢ ( 𝑥 𝐺 𝑦 ) = ( 𝐺 ‘ 〈 𝑥 , 𝑦 〉 ) | |
| 7 | 5 6 | eqeq12i | ⊢ ( ( 𝑥 𝐹 𝑦 ) = ( 𝑥 𝐺 𝑦 ) ↔ ( 𝐹 ‘ 〈 𝑥 , 𝑦 〉 ) = ( 𝐺 ‘ 〈 𝑥 , 𝑦 〉 ) ) |
| 8 | 4 7 | bitr4di | ⊢ ( 𝑧 = 〈 𝑥 , 𝑦 〉 → ( ( 𝐹 ‘ 𝑧 ) = ( 𝐺 ‘ 𝑧 ) ↔ ( 𝑥 𝐹 𝑦 ) = ( 𝑥 𝐺 𝑦 ) ) ) |
| 9 | 8 | ralxp | ⊢ ( ∀ 𝑧 ∈ ( 𝐴 × 𝐵 ) ( 𝐹 ‘ 𝑧 ) = ( 𝐺 ‘ 𝑧 ) ↔ ∀ 𝑥 ∈ 𝐴 ∀ 𝑦 ∈ 𝐵 ( 𝑥 𝐹 𝑦 ) = ( 𝑥 𝐺 𝑦 ) ) |
| 10 | 9 | anbi2i | ⊢ ( ( ( 𝐴 × 𝐵 ) = ( 𝐶 × 𝐷 ) ∧ ∀ 𝑧 ∈ ( 𝐴 × 𝐵 ) ( 𝐹 ‘ 𝑧 ) = ( 𝐺 ‘ 𝑧 ) ) ↔ ( ( 𝐴 × 𝐵 ) = ( 𝐶 × 𝐷 ) ∧ ∀ 𝑥 ∈ 𝐴 ∀ 𝑦 ∈ 𝐵 ( 𝑥 𝐹 𝑦 ) = ( 𝑥 𝐺 𝑦 ) ) ) |
| 11 | 1 10 | bitrdi | ⊢ ( ( 𝐹 Fn ( 𝐴 × 𝐵 ) ∧ 𝐺 Fn ( 𝐶 × 𝐷 ) ) → ( 𝐹 = 𝐺 ↔ ( ( 𝐴 × 𝐵 ) = ( 𝐶 × 𝐷 ) ∧ ∀ 𝑥 ∈ 𝐴 ∀ 𝑦 ∈ 𝐵 ( 𝑥 𝐹 𝑦 ) = ( 𝑥 𝐺 𝑦 ) ) ) ) |