Metamath Proof Explorer

Theorem moor

Description: "At most one" is still the case when a disjunct is removed. (Contributed by NM, 5-Apr-2004)

Ref Expression
Assertion moor 
|- ( E* x ( ph \/ ps ) -> E* x ph )

Proof

Step Hyp Ref Expression
1 orc 
 |-  ( ph -> ( ph \/ ps ) )
2 1 moimi 
 |-  ( E* x ( ph \/ ps ) -> E* x ph )