Metamath Proof Explorer

Theorem tsor1

Description: A Tseitin axiom for logical disjunction, in deduction form. (Contributed by Giovanni Mascellani, 25-Mar-2018)

Ref Expression
Assertion tsor1 
|- ( th -> ( ( ph \/ ps ) \/ -. ( ph \/ ps ) ) )

Proof

Step Hyp Ref Expression
1 exmidd 
 |-  ( th -> ( ( ph \/ ps ) \/ -. ( ph \/ ps ) ) )