Metamath Proof Explorer


Theorem mpjao3danOLD

Description: Obsolete version of mpjao3dan as of 17-Apr-2024. (Contributed by Thierry Arnoux, 13-Apr-2018) (New usage is discouraged.) (Proof modification is discouraged.)

Ref Expression
Hypotheses mpjao3dan.1
|- ( ( ph /\ ps ) -> ch )
mpjao3dan.2
|- ( ( ph /\ th ) -> ch )
mpjao3dan.3
|- ( ( ph /\ ta ) -> ch )
mpjao3dan.4
|- ( ph -> ( ps \/ th \/ ta ) )
Assertion mpjao3danOLD
|- ( ph -> ch )

Proof

Step Hyp Ref Expression
1 mpjao3dan.1
 |-  ( ( ph /\ ps ) -> ch )
2 mpjao3dan.2
 |-  ( ( ph /\ th ) -> ch )
3 mpjao3dan.3
 |-  ( ( ph /\ ta ) -> ch )
4 mpjao3dan.4
 |-  ( ph -> ( ps \/ th \/ ta ) )
5 1 2 jaodan
 |-  ( ( ph /\ ( ps \/ th ) ) -> ch )
6 df-3or
 |-  ( ( ps \/ th \/ ta ) <-> ( ( ps \/ th ) \/ ta ) )
7 4 6 sylib
 |-  ( ph -> ( ( ps \/ th ) \/ ta ) )
8 5 3 7 mpjaodan
 |-  ( ph -> ch )