Metamath Proof Explorer


Theorem 3ornot23VD

Description: Virtual deduction proof of 3ornot23 . The following user's proof is completed by invoking mmj2's unify command and using mmj2's StepSelector to pick all remaining steps of the Metamath proof.

1:: |- (. ( -. ph /\ -. ps ) ->. ( -. ph /\ -. ps ) ).
2:: |- (. ( -. ph /\ -. ps ) ,. ( ch \/ ph \/ ps ) ->. ( ch \/ ph \/ ps ) ).
3:1,?: e1a |- (. ( -. ph /\ -. ps ) ->. -. ph ).
4:1,?: e1a |- (. ( -. ph /\ -. ps ) ->. -. ps ).
5:3,4,?: e11 |- (. ( -. ph /\ -. ps ) ->. -. ( ph \/ ps ) ).
6:2,?: e2 |- (. ( -. ph /\ -. ps ) ,. ( ch \/ ph \/ ps ) ->. ( ch \/ ( ph \/ ps ) ) ).
7:5,6,?: e12 |- (. ( -. ph /\ -. ps ) ,. ( ch \/ ph \/ ps ) ->. ch ).
8:7: |- (. ( -. ph /\ -. ps ) ->. ( ( ch \/ ph \/ ps ) -> ch ) ).
qed:8: |- ( ( -. ph /\ -. ps ) -> ( ( ch \/ ph \/ ps ) -> ch ) )
(Contributed by Alan Sare, 31-Dec-2011) (Proof modification is discouraged.) (New usage is discouraged.)

Ref Expression
Assertion 3ornot23VD ( ( ¬ 𝜑 ∧ ¬ 𝜓 ) → ( ( 𝜒𝜑𝜓 ) → 𝜒 ) )

Proof

Step Hyp Ref Expression
1 idn1 (    ( ¬ 𝜑 ∧ ¬ 𝜓 )    ▶    ( ¬ 𝜑 ∧ ¬ 𝜓 )    )
2 simpl ( ( ¬ 𝜑 ∧ ¬ 𝜓 ) → ¬ 𝜑 )
3 1 2 e1a (    ( ¬ 𝜑 ∧ ¬ 𝜓 )    ▶    ¬ 𝜑    )
4 simpr ( ( ¬ 𝜑 ∧ ¬ 𝜓 ) → ¬ 𝜓 )
5 1 4 e1a (    ( ¬ 𝜑 ∧ ¬ 𝜓 )    ▶    ¬ 𝜓    )
6 ioran ( ¬ ( 𝜑𝜓 ) ↔ ( ¬ 𝜑 ∧ ¬ 𝜓 ) )
7 6 simplbi2 ( ¬ 𝜑 → ( ¬ 𝜓 → ¬ ( 𝜑𝜓 ) ) )
8 3 5 7 e11 (    ( ¬ 𝜑 ∧ ¬ 𝜓 )    ▶    ¬ ( 𝜑𝜓 )    )
9 idn2 (    ( ¬ 𝜑 ∧ ¬ 𝜓 )    ,    ( 𝜒𝜑𝜓 )    ▶    ( 𝜒𝜑𝜓 )    )
10 3orass ( ( 𝜒𝜑𝜓 ) ↔ ( 𝜒 ∨ ( 𝜑𝜓 ) ) )
11 10 biimpi ( ( 𝜒𝜑𝜓 ) → ( 𝜒 ∨ ( 𝜑𝜓 ) ) )
12 9 11 e2 (    ( ¬ 𝜑 ∧ ¬ 𝜓 )    ,    ( 𝜒𝜑𝜓 )    ▶    ( 𝜒 ∨ ( 𝜑𝜓 ) )    )
13 orel2 ( ¬ ( 𝜑𝜓 ) → ( ( 𝜒 ∨ ( 𝜑𝜓 ) ) → 𝜒 ) )
14 8 12 13 e12 (    ( ¬ 𝜑 ∧ ¬ 𝜓 )    ,    ( 𝜒𝜑𝜓 )    ▶    𝜒    )
15 14 in2 (    ( ¬ 𝜑 ∧ ¬ 𝜓 )    ▶    ( ( 𝜒𝜑𝜓 ) → 𝜒 )    )
16 15 in1 ( ( ¬ 𝜑 ∧ ¬ 𝜓 ) → ( ( 𝜒𝜑𝜓 ) → 𝜒 ) )