Description: Deduction joining 3 implications to form implication of conjunctions. (Contributed by NM, 24-Feb-2005)
Ref | Expression | ||
---|---|---|---|
Hypotheses | 3anim123d.1 | |
|
3anim123d.2 | |
||
3anim123d.3 | |
||
Assertion | 3anim123d | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | 3anim123d.1 | |
|
2 | 3anim123d.2 | |
|
3 | 3anim123d.3 | |
|
4 | 1 2 | anim12d | |
5 | 4 3 | anim12d | |
6 | df-3an | |
|
7 | df-3an | |
|
8 | 5 6 7 | 3imtr4g | |