Description: A lemma for introducing a universal quantifier, in inference form. (Contributed by Giovanni Mascellani, 30-May-2019)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | alrimii.1 | |- F/ y ph |
|
| alrimii.2 | |- ( ph -> ps ) |
||
| alrimii.3 | |- ( [. y / x ]. ch <-> ps ) |
||
| alrimii.4 | |- F/ y ch |
||
| Assertion | alrimii | |- ( ph -> A. x ch ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | alrimii.1 | |- F/ y ph |
|
| 2 | alrimii.2 | |- ( ph -> ps ) |
|
| 3 | alrimii.3 | |- ( [. y / x ]. ch <-> ps ) |
|
| 4 | alrimii.4 | |- F/ y ch |
|
| 5 | 2 3 | sylibr | |- ( ph -> [. y / x ]. ch ) |
| 6 | 1 5 | alrimi | |- ( ph -> A. y [. y / x ]. ch ) |
| 7 | nfsbc1v | |- F/ x [. y / x ]. ch |
|
| 8 | sbceq2a | |- ( y = x -> ( [. y / x ]. ch <-> ch ) ) |
|
| 9 | 7 4 8 | cbvalv1 | |- ( A. y [. y / x ]. ch <-> A. x ch ) |
| 10 | 6 9 | sylib | |- ( ph -> A. x ch ) |