Description: Inference removing a negated conjunct in a disjunction of an antecedent if this conjunct is part of the disjunction. (Contributed by Alexander van der Vekens, 3-Nov-2017) (Proof shortened by Wolf Lammen, 21-Sep-2018)
Ref | Expression | ||
---|---|---|---|
Hypothesis | jaoi2.1 | |
|
Assertion | jaoi2 | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | jaoi2.1 | |
|
2 | pm5.63 | |
|
3 | 2 1 | sylbi | |