Description: Define the set of functions (morphisms of sets) between two sets. Same as df-map with arguments swapped. TODO: prove the same staple lemmas as for ^m .
Remark: one may define -Set-> = ( x e. dom Struct , y e. dom Struct |-> { f | f : ( Basex ) --> ( Basey ) } ) so that for morphisms between other structures, one could write ... = { f e. ( x -Set-> y ) | ... } .
(Contributed by BJ, 11-Apr-2020)
Ref | Expression | ||
---|---|---|---|
Assertion | df-bj-sethom | ⊢ Set⟶ = ( 𝑥 ∈ V , 𝑦 ∈ V ↦ { 𝑓 ∣ 𝑓 : 𝑥 ⟶ 𝑦 } ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
0 | csethom | ⊢ Set⟶ | |
1 | vx | ⊢ 𝑥 | |
2 | cvv | ⊢ V | |
3 | vy | ⊢ 𝑦 | |
4 | vf | ⊢ 𝑓 | |
5 | 4 | cv | ⊢ 𝑓 |
6 | 1 | cv | ⊢ 𝑥 |
7 | 3 | cv | ⊢ 𝑦 |
8 | 6 7 5 | wf | ⊢ 𝑓 : 𝑥 ⟶ 𝑦 |
9 | 8 4 | cab | ⊢ { 𝑓 ∣ 𝑓 : 𝑥 ⟶ 𝑦 } |
10 | 1 3 2 2 9 | cmpo | ⊢ ( 𝑥 ∈ V , 𝑦 ∈ V ↦ { 𝑓 ∣ 𝑓 : 𝑥 ⟶ 𝑦 } ) |
11 | 0 10 | wceq | ⊢ Set⟶ = ( 𝑥 ∈ V , 𝑦 ∈ V ↦ { 𝑓 ∣ 𝑓 : 𝑥 ⟶ 𝑦 } ) |