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Description: Used to rederive standard propositional axioms from Lukasiewicz'. (Contributed by NM, 22-Dec-2002) (Proof modification is discouraged.) (New usage is discouraged.)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | luklem7 | |- ( ( ph -> ( ps -> ch ) ) -> ( ps -> ( ph -> ch ) ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | luk-1 | |- ( ( ph -> ( ps -> ch ) ) -> ( ( ( ps -> ch ) -> ch ) -> ( ph -> ch ) ) ) |
|
| 2 | luklem5 | |- ( ps -> ( ( ps -> ch ) -> ps ) ) |
|
| 3 | luk-1 | |- ( ( ( ps -> ch ) -> ps ) -> ( ( ps -> ch ) -> ( ( ps -> ch ) -> ch ) ) ) |
|
| 4 | 2 3 | luklem1 | |- ( ps -> ( ( ps -> ch ) -> ( ( ps -> ch ) -> ch ) ) ) |
| 5 | luklem6 | |- ( ( ( ps -> ch ) -> ( ( ps -> ch ) -> ch ) ) -> ( ( ps -> ch ) -> ch ) ) |
|
| 6 | 4 5 | luklem1 | |- ( ps -> ( ( ps -> ch ) -> ch ) ) |
| 7 | luk-1 | |- ( ( ps -> ( ( ps -> ch ) -> ch ) ) -> ( ( ( ( ps -> ch ) -> ch ) -> ( ph -> ch ) ) -> ( ps -> ( ph -> ch ) ) ) ) |
|
| 8 | 6 7 | ax-mp | |- ( ( ( ( ps -> ch ) -> ch ) -> ( ph -> ch ) ) -> ( ps -> ( ph -> ch ) ) ) |
| 9 | 1 8 | luklem1 | |- ( ( ph -> ( ps -> ch ) ) -> ( ps -> ( ph -> ch ) ) ) |