Description: Deduction from a subclass relationship of binary relations. (Contributed by NM, 30-Apr-2004)
Ref | Expression | ||
---|---|---|---|
Hypothesis | ssbrd.1 | |
|
Assertion | ssbrd | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | ssbrd.1 | |
|
2 | 1 | sseld | |
3 | df-br | |
|
4 | df-br | |
|
5 | 2 3 4 | 3imtr4g | |