Description: Function returning the isomorphisms of the category c . Definition 3.8 of Adamek p. 28, and definition in Lang p. 54. (Contributed by FL, 9-Jun-2014) (Revised by Mario Carneiro, 2-Jan-2017)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | df-iso | |- Iso = ( c e. Cat |-> ( ( x e. _V |-> dom x ) o. ( Inv ` c ) ) ) | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 0 | ciso | |- Iso | |
| 1 | vc | |- c | |
| 2 | ccat | |- Cat | |
| 3 | vx | |- x | |
| 4 | cvv | |- _V | |
| 5 | 3 | cv | |- x | 
| 6 | 5 | cdm | |- dom x | 
| 7 | 3 4 6 | cmpt | |- ( x e. _V |-> dom x ) | 
| 8 | cinv | |- Inv | |
| 9 | 1 | cv | |- c | 
| 10 | 9 8 | cfv | |- ( Inv ` c ) | 
| 11 | 7 10 | ccom | |- ( ( x e. _V |-> dom x ) o. ( Inv ` c ) ) | 
| 12 | 1 2 11 | cmpt | |- ( c e. Cat |-> ( ( x e. _V |-> dom x ) o. ( Inv ` c ) ) ) | 
| 13 | 0 12 | wceq | |- Iso = ( c e. Cat |-> ( ( x e. _V |-> dom x ) o. ( Inv ` c ) ) ) |