Description: Lemma for nic-id . (Contributed by Jeff Hoffman, 17-Nov-2007) (Proof modification is discouraged.) (New usage is discouraged.)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | nic-idlem1 | |- ( ( th -/\ ( ta -/\ ( ta -/\ ta ) ) ) -/\ ( ( ( ph -/\ ( ch -/\ ps ) ) -/\ th ) -/\ ( ( ph -/\ ( ch -/\ ps ) ) -/\ th ) ) ) | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | nic-ax | |- ( ( ph -/\ ( ch -/\ ps ) ) -/\ ( ( ta -/\ ( ta -/\ ta ) ) -/\ ( ( ph -/\ ch ) -/\ ( ( ph -/\ ph ) -/\ ( ph -/\ ph ) ) ) ) ) | |
| 2 | 1 | nic-imp | |- ( ( th -/\ ( ta -/\ ( ta -/\ ta ) ) ) -/\ ( ( ( ph -/\ ( ch -/\ ps ) ) -/\ th ) -/\ ( ( ph -/\ ( ch -/\ ps ) ) -/\ th ) ) ) |