Description: Elementhood in the class of functions. (Contributed by Peter Mazsa, 24-Jul-2021)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | elfunsALTV | |- ( F e. FunsALTV <-> ( ,~ F e. CnvRefRels /\ F e. Rels ) )  | 
				
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | dffunsALTV |  |-  FunsALTV = { x e. Rels | ,~ x e. CnvRefRels } | 
						|
| 2 | cosseq | |- ( x = F -> ,~ x = ,~ F )  | 
						|
| 3 | 2 | eleq1d | |- ( x = F -> ( ,~ x e. CnvRefRels <-> ,~ F e. CnvRefRels ) )  | 
						
| 4 | 1 3 | rabeqel | |- ( F e. FunsALTV <-> ( ,~ F e. CnvRefRels /\ F e. Rels ) )  |