Description: A consequence of nonfreeness in the antecedent and the consequent of an implication. (Contributed by BJ, 27-Aug-2023)
Ref | Expression | ||
---|---|---|---|
Assertion | bj-nnfim1 |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | bj-nnfe | ||
2 | bj-nnfa | ||
3 | imim12 | ||
4 | 3 | imp | |
5 | 1 2 4 | syl2an |