Description: A syllogism inference from two biconditionals. (Contributed by NM, 12-Mar-1993)
Ref | Expression | ||
---|---|---|---|
Hypotheses | bitr4di.1 | |
|
bitr4di.2 | |
||
Assertion | bitr4di | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | bitr4di.1 | |
|
2 | bitr4di.2 | |
|
3 | 2 | bicomi | |
4 | 1 3 | bitrdi | |