Metamath Proof Explorer


Theorem int2

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 ) ).

Proof

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 ) ).