This is an inofficial mirror of http://metamath.tirix.org for personal testing of a visualizer extension only.
Description: An operation's value belongs to its codomain. (Contributed by Mario Carneiro, 29-Dec-2016)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | fovcdmd.1 | ⊢ ( 𝜑 → 𝐹 : ( 𝑅 × 𝑆 ) ⟶ 𝐶 ) | |
| fovcdmd.2 | ⊢ ( 𝜑 → 𝐴 ∈ 𝑅 ) | ||
| fovcdmd.3 | ⊢ ( 𝜑 → 𝐵 ∈ 𝑆 ) | ||
| Assertion | fovcdmd | ⊢ ( 𝜑 → ( 𝐴 𝐹 𝐵 ) ∈ 𝐶 ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | fovcdmd.1 | ⊢ ( 𝜑 → 𝐹 : ( 𝑅 × 𝑆 ) ⟶ 𝐶 ) | |
| 2 | fovcdmd.2 | ⊢ ( 𝜑 → 𝐴 ∈ 𝑅 ) | |
| 3 | fovcdmd.3 | ⊢ ( 𝜑 → 𝐵 ∈ 𝑆 ) | |
| 4 | fovcdm | ⊢ ( ( 𝐹 : ( 𝑅 × 𝑆 ) ⟶ 𝐶 ∧ 𝐴 ∈ 𝑅 ∧ 𝐵 ∈ 𝑆 ) → ( 𝐴 𝐹 𝐵 ) ∈ 𝐶 ) | |
| 5 | 1 2 3 4 | syl3anc | ⊢ ( 𝜑 → ( 𝐴 𝐹 𝐵 ) ∈ 𝐶 ) |