Description: Used to rederive the Lukasiewicz axioms from Russell-Bernays'. (Contributed by Anthony Hart, 18-Aug-2011) (Proof modification is discouraged.) (New usage is discouraged.)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | rblem2 | |- ( -. ( ch \/ ph ) \/ ( ch \/ ( ph \/ ps ) ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | rb-ax2 | |- ( -. ( ps \/ ph ) \/ ( ph \/ ps ) ) |
|
| 2 | rb-ax3 | |- ( -. ph \/ ( ps \/ ph ) ) |
|
| 3 | 1 2 | rbsyl | |- ( -. ph \/ ( ph \/ ps ) ) |
| 4 | rb-ax1 | |- ( -. ( -. ph \/ ( ph \/ ps ) ) \/ ( -. ( ch \/ ph ) \/ ( ch \/ ( ph \/ ps ) ) ) ) |
|
| 5 | 3 4 | anmp | |- ( -. ( ch \/ ph ) \/ ( ch \/ ( ph \/ ps ) ) ) |