Description: Substitution for the left-hand side in an equality. Class version of eqsb1 . (Contributed by Andrew Salmon, 29-Jun-2011) Avoid ax-13 . (Revised by Wolf Lammen, 29-Apr-2023)
Ref | Expression | ||
---|---|---|---|
Assertion | eqsbc1 | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | dfsbcq | |
|
2 | eqeq1 | |
|
3 | sbsbc | |
|
4 | eqsb1 | |
|
5 | 3 4 | bitr3i | |
6 | 1 2 5 | vtoclbg | |