Description: Distribution of class substitution over alternate ordered pairs. (Contributed by Scott Fenton, 25-Sep-2015)
Ref | Expression | ||
---|---|---|---|
Assertion | sbcaltop | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | nfcsb1v | |
|
2 | nfcsb1v | |
|
3 | 1 2 | nfaltop | |
4 | 3 | a1i | |
5 | csbeq1a | |
|
6 | altopeq1 | |
|
7 | 5 6 | syl | |
8 | csbeq1a | |
|
9 | altopeq2 | |
|
10 | 8 9 | syl | |
11 | 7 10 | eqtrd | |
12 | 4 11 | csbiegf | |