Description: Syllogism followed by rotation of three antecedents. Proposition 23 of Frege1879 p. 42. (Contributed by RP, 24-Dec-2019) (Proof modification is discouraged.)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | frege23 |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | frege18 | ||
| 2 | frege22 | ||
| 3 | 1 2 | ax-mp |