Description: The value of a function that maps from B to A . (Contributed by AV, 2-Feb-2023)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | mapfvd.m | ⊢ 𝑀 = ( 𝐴 ↑m 𝐵 ) | |
| mapfvd.f | ⊢ ( 𝜑 → 𝐹 ∈ 𝑀 ) | ||
| mapfvd.x | ⊢ ( 𝜑 → 𝑋 ∈ 𝐵 ) | ||
| Assertion | mapfvd | ⊢ ( 𝜑 → ( 𝐹 ‘ 𝑋 ) ∈ 𝐴 ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | mapfvd.m | ⊢ 𝑀 = ( 𝐴 ↑m 𝐵 ) | |
| 2 | mapfvd.f | ⊢ ( 𝜑 → 𝐹 ∈ 𝑀 ) | |
| 3 | mapfvd.x | ⊢ ( 𝜑 → 𝑋 ∈ 𝐵 ) | |
| 4 | elmapi | ⊢ ( 𝐹 ∈ ( 𝐴 ↑m 𝐵 ) → 𝐹 : 𝐵 ⟶ 𝐴 ) | |
| 5 | ffvelcdm | ⊢ ( ( 𝐹 : 𝐵 ⟶ 𝐴 ∧ 𝑋 ∈ 𝐵 ) → ( 𝐹 ‘ 𝑋 ) ∈ 𝐴 ) | |
| 6 | 5 | expcom | ⊢ ( 𝑋 ∈ 𝐵 → ( 𝐹 : 𝐵 ⟶ 𝐴 → ( 𝐹 ‘ 𝑋 ) ∈ 𝐴 ) ) |
| 7 | 3 4 6 | syl2imc | ⊢ ( 𝐹 ∈ ( 𝐴 ↑m 𝐵 ) → ( 𝜑 → ( 𝐹 ‘ 𝑋 ) ∈ 𝐴 ) ) |
| 8 | 7 1 | eleq2s | ⊢ ( 𝐹 ∈ 𝑀 → ( 𝜑 → ( 𝐹 ‘ 𝑋 ) ∈ 𝐴 ) ) |
| 9 | 2 8 | mpcom | ⊢ ( 𝜑 → ( 𝐹 ‘ 𝑋 ) ∈ 𝐴 ) |