Description: Version of sbcel1g when substituting a set. (Note: one could have a corresponding version of sbcel12 when substituting a set, but the point here is that the antecedent of sbcel1g is not needed when substituting a set.) (Contributed by BJ, 6-Oct-2018)
Ref | Expression | ||
---|---|---|---|
Assertion | bj-sbel1 | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | sbsbc | |
|
2 | sbcel1g | |
|
3 | 2 | elv | |
4 | 1 3 | bitri | |