Description: Subclass theorem for function. (Contributed by NM, 16-Aug-1994) (Proof shortened by Mario Carneiro, 24-Jun-2014) (Revised by Peter Mazsa, 22-Sep-2021)
Ref | Expression | ||
---|---|---|---|
Assertion | funALTVss |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | cossss | ||
2 | sstr2 | ||
3 | 1 2 | syl | |
4 | relss | ||
5 | 3 4 | anim12d | |
6 | dffunALTV2 | ||
7 | dffunALTV2 | ||
8 | 5 6 7 | 3imtr4g |