Description: Deduction that substitutes equal classes into membership. (Contributed by NM, 14-Dec-2004)
Ref | Expression | ||
---|---|---|---|
Hypotheses | eleqtrrd.1 | |
|
eleqtrrd.2 | |
||
Assertion | eleqtrrd | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | eleqtrrd.1 | |
|
2 | eleqtrrd.2 | |
|
3 | 2 | eqcomd | |
4 | 1 3 | eleqtrd | |