Description: Inference form of df-vd1 with the virtual deduction as the assertion. (Contributed by Alan Sare, 14-Nov-2011) (Proof modification is discouraged.) (New usage is discouraged.)
Ref | Expression | ||
---|---|---|---|
Hypothesis | dfvd1ir.1 | |- ( ph -> ps ) |
|
Assertion | dfvd1ir | |- (. ph ->. ps ). |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | dfvd1ir.1 | |- ( ph -> ps ) |
|
2 | df-vd1 | |- ( (. ph ->. ps ). <-> ( ph -> ps ) ) |
|
3 | 1 2 | mpbir | |- (. ph ->. ps ). |