Description: The virtual deduction introduction rule of converting the end virtual hypothesis of 2 virtual hypotheses into an antecedent. Conventional form of int2 is ex . (Contributed by Alan Sare, 23-Apr-2015) (Proof modification is discouraged.) (New usage is discouraged.)
Ref | Expression | ||
---|---|---|---|
Hypothesis | int2.1 | |- (. (. ph ,. ps ). ->. ch ). |
|
Assertion | int2 | |- (. ph ->. ( ps -> ch ) ). |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | int2.1 | |- (. (. ph ,. ps ). ->. ch ). |
|
2 | 1 | dfvd2ani | |- ( ( ph /\ ps ) -> ch ) |
3 | 2 | ex | |- ( ph -> ( ps -> ch ) ) |
4 | 3 | dfvd1ir | |- (. ph ->. ( ps -> ch ) ). |