Description: A mixed syllogism inference from a nested implication and a biconditional. (Contributed by NM, 21-Jun-1993)
Ref | Expression | ||
---|---|---|---|
Hypotheses | syl6ib.1 | |
|
syl6ib.2 | |
||
Assertion | syl6ib | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | syl6ib.1 | |
|
2 | syl6ib.2 | |
|
3 | 2 | biimpi | |
4 | 1 3 | syl6 | |